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those four earlier sun-spot cycles, at least, we had had, on the Dr. Klein has carried out between September, 184, whole, wetter years about sun-spot maxima than about the March, 1891, five separate consecutive series of experie minima. A good deal was written on the subject (as your own | with “ Aminol,” with the object of testing its applicabia columns show) in the seventies; and the data used seem to have the treatment of certain external disease processes. El been generally those of annual rainfall. Of late, apparently, the sults are recorded in a report, the summary and conclusie matter has attracted less notice ; for the reason (I suppose) that which were publi-hed last year with his full approval the correspondence referred to has not been maintained, and strength of solution employed in the first four series (which recent facts have seemed rather against the theory of a causal only of a tentative nature with a view to arrive at a relation between the two orders of phenomena.

strength of solution for practical application) was I in 600 Thus the teaching of the curve here given appears to har the fifth series a solution of the strength of 1 in 600 monize, in general, with known facts about annual rainfall. I do Dr. Klein's letter leads one to suppose that he operare: not propose to try and weigh the data so far as they may be with the lalter strength. considered to favour the theory just indicated (earlier and greater The pathogenic germs selected for testing the powad part of the curve), nor the data which may be considered disinfeciant were : spores of Bacillus anthracis, spored adverse (in the short, later part). It seems to me that the curve Bacillus anthracis, Staphylococcus aureus, Bacillus dichte may be usefully studied per se, apart from any relation to sun and Streptococcus erysi pelatis. Amongst the results citu spots. Thus we might note the fact that all those maxima ! with the solution of the strength of 1 in 6000 his reput where our summers have got to a turning point from wet to dry tions the following : In Series IV., On Staphylocaccia have been quite near the beginnings of the decades. The dates which may be taken as the most resistant microbe any are 1830, 1839, 1850, 1861, and 1880. The curve ends at 1890 those associated with surgical and other external disease (the final point representing, of course, 1888-92), and the posi cesses, the “Aminol” solution (1 in 6000) did prodes tion of this point, together with the date, seem to warrant our effect, though a limited one, after two hours already, and il

twenty-four hours destroyed the microbes." In Ses

" Aminol' solution (1 in 6000) kills the Bacillus digitira RAIN DAYS.

two hours. This was confirmed in Series III." In this

nection it deserves to be noted that I possess already a

RAN DAYS SUNSP

evidence, which will be published in due course, of consis 44160

successes obtained in practice not only with the solutie si 42 140

strength of 1 in 5000, but also with dilutions of the sant, 40 120

to I in 20,000. 38 100

Dr. Klein's statement of the results which he obtained 36 80

“ Aminol” in the strength of 1 in 600 is misleading. Hes
"Spores of Anthrax bacilli remained unaffected as
hours, only after an exposure of twenty-four hours !
number of living spores decrease ; but some escaped an
tion even after so long an exposure. Now what are the
I quote from Dr. Klein's report:-

“Spores of Bacillus anthracis after good gore 1825 28 31 34 37 40 43 46 49'52 '55 58 61 64 67 70 73 76 79 82 85 88 91

1, 2, 8, and 12 hours “Spores of Bacillus anthracis after growih rede 24 hours

from 100 Smoothed curve of rain days in Summer at Greenwich, with curve of Is it putting the case fairly or even clearly, seeing that s Sun-spots.

were made between twelve and twenty-four hours,

only after twenty-four hours did the number deres looking for an early descent of the curve, and a commencing and seeing that only 6 per cent. remained after twessi series of (on the average) drier summers than we have had hours ? Is not that a decrease practically amount lately.

disinfection ? Would it be extravagant to assume that We might also note that the minima of the curve have ranged significant percentage remaining would be eliminate: 1 from the fives to the eights. Thus we have, 1827, 1835, 1845, I very little longer exposure (say another hour), and is the 1857, 1868, 1885. Should the recurrence continue, we might doubt that a solution of the strength of 1 in 500 gr look for the next minimum about 1895-1898. Of course there would have accomplished complete disinfection in a marks may be difference of opinion as to the strength of the presump. I time than twenty-four hours ? But in order to illustrate tion here afforded for such a forecast, and no good reason is nificance of the results actually obtained with this solis offered (beyond experience) why the curve should now take the strength of 1 in 600, let us see which other disinfectants course roughly indicated.

anthrax spores in twenty-four hours. I quote from " It is not at variance with the above view that there is reason, Disinfection," abstracted and translated by Whitelezza it would appear, to anticipate soon a series of wetter years. In an lished by the New Sydenham Society :article contributed to the Times of October 22 last year (cited in (1) "For practical purposes a disinfectant should not Nature, vol. xliv. p. 630) Mr. Symons says: “There is no doubt much longer than twenty-four hours." that since 1887, at all events, the rainfall over England has (2) "Except chlorine, bromine, and iodine, only se been much below the average ; and a consideration of all the chloride, osmic acid, and potassic permanganate (5 pc facts leads to the conclusion that such a period of scarcity is destroyed anthrax spores within twenty-four hours. Sit very likely to be followed by one of abundance, and that the cent. solution of permanganate is inadmissible for disse coming few years will probably be more rainy than those re. in bulk, and osmic acid is out of the question, we have cently experienced, although possibly the increase will not ! mercuric chloride and iodine, bromine, and chlorine occur in the summer months—at a time when it would be most The strengths in which the above-named substances so noticed.”

A. B. M. in destroying anthrax spores in twenty-four hours are so

Koch's tables thus :“Aminol.”

Permanganate, aqueous solution 5 per cent (1 in 2 My attention has only now been called to the letter of Dr.

Bromine Klein, which appeared in Nature, ante, p. 149.

Chlorine To the remarks referring to “ Aminol” (with Periodate I am

Iodine in no way concerned) I desire, with your kind permission, to

Mercuric chloride ,

I per cent (I in II. make the following reply, as they contain inaccuracies which,

Osmic acid if not corrected, must do me injury.

Now put against this the fact, quoted above, that Dr. Leo The samples of “Aminol” alluded to by Dr. Klein were “that 'Aminol,' strength 1 in 600, killed 94 per cent of sent by me to a number of medical practitioners who had kindly spores in twenty-four hours,” and further (I am qezas consented to give it a trial. The strength of the samples was report again), “that this solution is a perfectly harmles I in 5000.

regards the human organism ; therefore no undesirabe

[graphic]

(1 in 100

could ensue owing to its being absorbed ; this is well the whole matter, one has only to compare the actual facts to be the fact with some antiseptics, as in carbolic acid

of the case, as regards“ Aminol” of the strength of 1 in ations or in the use of perchloride of mercury."

5000, with the molto put on the leaflet and the inscription on is not all this clearly establish the claim of " Aminol” to the label of the samples. For Mr. Wollheim quotes Koch led not only a true disinfectant, but a most potent and a to the effect that no disinfectant can be called a true disinfectant safe one at the same tine ?

that does not kill spores, and notwithstanding that I have with all this (I mean what relates to its effect on anthrax

shown that “Aminol” even of the strength of 1 in 600 cannot 3) its application in medical and surgical practice has kill spores in 12 hours, yet Mr. Wollheim advertises the ig to do, unless it be to demonstrate its comparative po Aminol ” of the strength of 1 in 5000 as “a true disinfectfor, a Dr. Klein himself points out in his report, “The ant." A true disinfectant kills spores after short exposure ; a of Bacillus anthracis may be left out of consideration, as

substance that requires many hours to do so cannot claim the o not occur in the living body ; under these conditions the

name of a specific disinfectant. Vinegar, dilute acids, alkalies, 'us anthracis is always sp oreless; a malignant carbuncle of and a host of substances affect spores after exposure for many in contains the Bacillus anthracis only in the sporeless

hours (8, 12, and 24 hours), yet no one would consider these and in infection with anthrax generally the bacilli are

substances as specific disinfectants. 5 in the sporefree state both in the blood and in the

Again, a substance used in a certain strength (say I in 600)

may have considerable disinfecting power on non-spore bearing at is of real importance in practice is the effect of “Ami microbes, with or without having any conspicuous action on on the other pathogenic germs on which Dr. Klein has spores. The same substance more diluted (say I in 5000) may it. And here again his letter states the case in a manner

have retained such action only to a very insignificant degree. is apt to mislead : “ Anthrar bacilli, Staphylococcus

Take for instance perchloride of mercury; while this substance s and others were destroyed, but only aster a lengthy ex: is a powerful disinfectant when used in the strength of i in

500, i in 1000, even i in 2000, it has greatly less effect when w what does his report say? " Series V. From this series

used in more increased dilution. I be seen, therefore, that the solution used in the same No one is justified in advertising perchloride of mercury of 600) acted very differently from that used in the previous the strength of 1 in 100,000 as “a true disinfectant," knowing iments (1 in 6000) inasmuch as the Staphylococcus aureus, that i in 500 or 1 in 1000 only can be so called. How much I was not killed heretofore in eight hours, was in this more does this hold good for a substance like “ Aminol," ice completely disinfected in that time, and was consider which even in the strength of 1 in 600 does not kill the spores reduced even in one hour. The sporeless Bacillus anthracis, of anthrax in 12 hours, a period which for practical purposes of lus diphtheria, and Streptococcus erysipelatis were killed in disinfection is out of the question.

E. KLEIN. your." Can it be fairly said, then, that these were killed 19, Earl's Court Square, S.W., January 9. ifter lengthy exposure, and does the word "only" apply at all : one-hour results, when it is considered that there was no jade under the one hour? What is there to show that those

Super-abundant Rain. rich there was no growth aster one hour's exposure to the ectant had not been killed after ten minutes already ?

IN NATURE of November 10 the fact that “very nearly one. es it not look, then, as if Dr. Klein had penned his letter

third " of the annual rainfall fell in one month at Nant-y-Glyn, out consulting either his notes or his report?

in North Wales, is recorded as “remarkable.” word in conclusion. Dr. Klein, for whom perhaps nobody But at Peshawar, on the north-west frontier of India, we tains a higher personal regard than myself, may rest assured received during last August a rainfall of 17.75 inches, the averhe designation, “a true disinfectant," is meant by me to age local annual fall, calculated from the last fifteen years, being

only to such strengths of solutions of “ Aminol" as can | 13:51 inches. ate with those substances and their respective strengths to We therefore had very nearly sixteen months fall in one

Koch has accorded that appellation. Nor need he to month, and by far the largest portion of this fell in ten days of hend that anything has been or will ever be done by me the month. ionally committing him to what is not fully warranted I need hardly add that the whole valley was flooded, and 3 actual results as recorded in his authorized published that we have since paid for our super-abundant rain in the form

Hugo WOLLHEIM. of very prevalent and fatal malarious fever. H. COLLETT. -, Leadenhall Street, E.C., January 2.

Peshawar, December 19, 1892.
E point at issue between Mr. Wollheim and inyself is a
simple one, and needs no long explanation on behalf of
Wollheim. As you will see from the letter which you

Earthquake Shocks.
V printed in NATURE, ante, p. 149, Mr. Wollheim, with

There were two unmistakable shocks of earthquake on the y authority, has sent round a leaflet with my name on it, afternoon of Tuesday, January 3, the first at 2h. 15m. 155. panying bottles of Aminol,” stated to be “a true G.M.T., and the second at 2h. 17m. I was sitting in a railway ctant."

carriage at Severn Junction Station waiting for the Bristol pas. On this leaflet my name is introduced in a somewhat mis sengers, when I felt a sensible upward movement of the seat g manner, for it quotes to a large extent from my reports

(as if pushed from below) and saw the carriage sway. The lime and brine experiments on microbes without saying

movement was from south to north (i.e. at right angles to the t leaving the reader to infer that these reports of mine

railway). This was repeated four times in about six seconds. O “ Aminol."

At 2h. 17m. there were two more (less strong) shocks. The Ir. Wollheim never asked my permission or informed me carriage was placed in a siding, and there was no train at the

intention of sending with each sample boltle of “ Ami. station, and the air was calm and frosty. Ice was said to have such a leaflet. It is unnecessary to say that had he cracked near here at this time.

E. J. LOWE. me whether he could use my name on a wrapper of a Shirenewton Hall, Chepstow.

medicine I should have emphatically answered no. I recently informed me that he has cancelled the leaflet.

A Brilliant Meteor, 'he samples of “ Aminol” sent out were of the strength 5000, the experiments in which I showed that “Ami.

On Wednesday, January 7, at about 6.35 p.m., I was fortu. ossesses a certain disinfecting power were made with a nate enough to see a brilliant meteor descending a little north of h of 1 in 600. This strength did not kill spores of Castor. My attention was drawn to it by the brilliant light it

in 12 hours; 1 in 6000 did not kill Staphylococcus threw over the country. The head was a ball of dazzling white in 8 hours.

and the tail yellow, with red streaks. It disappeared before ibstance which, like the “Aminol” sent out (viz. 1 in

reaching the earth, and I heard no report or rushing sound cannot kill Staphylococcus aureus in 8 hours, and has whatever. ally no effect on spores of Bacillus anthracis cannot be As the duration was only a few seconds the above are more red "a true disinfectant."

impressions than observations.

W. POLLARD. how that Mr. Wollheim had a very strange idea about Pirton, Herts, January 7.

CHEMICAL SOCIETY'S MEMORIAL

published. Stas was born at Louvain on August 21,2) LECTURES.

He graduated as Doctor of Medicine. His tase

chemical research was evidenced in 1835, when, togei AT an extra meeting of the Chemical Society, held on with a friend, be investigated in an attic of his faute n December 13 last, this being the first anniversary house the crystalline substance phloridzin which they of the death of Stas, a paper was read and discussed extracted from the root bark of the apple tree. Hea which had been prepared for the occasion by Prof. J. W. tinued the study of this substance in Dumas' labore Mallet, F.R.S., of the University of Virginia, U.S.N.A. in Paris, and it is an interesting proof of the acum

-himself a high authority on atomic weight determina Berzelius that in his annual report on the progs tions, and well known to chemists through his papers on chemistry he referred to this first research made by the atomic weights of aluminium and gold, published by with praise, and a prediction of future eminence fare the Royal Society of London.

author. The lecture marks a new departure in the work of the The starting-point of the long train of research ra society. Hitherto our learned societies have been in the which his name will ever be associated was the rein habit of publishing more or less complete--it would mination of the atomic mass of carbon which Dunza probably be nearer the truth to say incomplete-obituary | he together undertook, in order to explain the I notices of their foreign members. The Chemical Society | noticed by Liebig and others, that the sum of the ca has come to the conclusion, however, that inasmuch as and hydrogen found in hydrocarbons by the combus: its foreign members are always men of great distinction process, as calculated from the carbon dioxide and rz who, as a rule, have lived a considerable number of years not unfrequently exceeded the quantity of matera a after accomplishing their life work, it will be to the ad- lyzed. As the result of this investigation, which vantage of its fellows and of chemists generally, if the carried out with unprecedented care and the moss obituary notices of foreign members take the form of borate precautions, the value hitherto accepted for at critical monographs of the subjects with which they have on the authority of Berzelius (76432 0=100) was principally dealt.

siderably reduced (to 75'005). In 1840 Stas was appe: The anniversary of the death of the foreign member Professor in the Ecole Royale Militaire at Brussels is obviously the most appropriate occasion for the de- held this post for more than a quarter of a century, livery of such a lecture. During the past year the society an affection of the bronchial tubes and larynx on has lost two of its foreign members : Hermann Kopp, him to give up lecturing. He then received an apua noted as an historian, as well as on account of his very ment in the Mint, but resigned this in 1872 on poco numerous exact determinations of atomic volumes and grounds, and withdrew into private life. He apo specific heats, and A. W. von Hofmann. The life and to have been a man of great independence of chua work of the first mentioned will form the subject of a Apart from his atomic weight investigations * lecture to be delivered on February 20 next, by Prof. much work of value in other departments. His ca Thorpe, the Treasurer of the Society, than whom no one of separating alkaloids from organic messes-13 is more qualified to undertake the task. Prof. Thorpe is | name is applicable-which has been of such service not only a pupil of the deceased chemist, but has rever- subsequent toxicological inquiries, was devised : ently followed in his footsteps-having very largely in the course of the inquiry into the celebrated Bear extended Kopp's observations on atomic volumes in an nicotine poisoning case. He examined into the me.cz elaborate investigation, the importance of which was hydrolysing fats for the purpose of a report o? recognised by the Chemical Society in 1881 through the chemical section of the London 1862 Exhibition 13 award to him of its first Longstaff medal.

nection with the preparation of international staza Von Hofmann, although originally a foreign member, he took an active part, along with Devile, in the became an ordinary member of the Chemical Society on into the properties of the platinum metals. It is a coming to England as professor at the school in Oxford also that he did important work for his Goverz Street, long since merged in what is now known as the investigating alloys for use in the construction of ande Royal College of Science, London. Hofmann was never Prof. Mallet prefaces his account of Stas's specs again regarded as a foreigner; he served the society | vestigations by an historical survey of the fundo both as foreign secretary and as president, filling one of ideas which have gradually led up to the questioald the vice-chairs during the remainder of his life. It is is the mass of an atom of a particular element felt that owing to the special nature of his relations to the in and beyond the days of Cavendish and Pries society and to english chemistry, it will be necessary to fact that atmospheric air was found of constant of deal with his case in an exceptional manner; it is there. constant composition was long a stumbling-block 3 fore hoped that in May next Lord Playfair-who was so way of clear distinction between a homogeneous intimately connected in his early days with chemical pound and a uniform mixture. To the labours ! science and with the society-in the first place will pic-Helmont, Boyle, and Boerhave much credit is due to ture the state of affairs chemical at and prior to the gradual advance towards the doctrine of the contra time of Hofmann's arrival in England. Sir F. Abel, of matter. The discoveries of Black and Caree Hofmann's first pupil and assistant, will follow with an brought it further into view, and it assumed its dee. account of Hofmann at the Royal College of Chemistry, ance and began to receive universal recognition calling to his aid for this purpose the remaining friends constant appeal to the balance which Lavoisier * and pupils of Hofmann. The coal-tar colour industry, taught others to make. Next came a comparison which has now attained such important dimensions, it is quantities of different substances, at first chietly the well known, had its origin in the Oxford Street laboratory, known acids and bases, which would enter into o and Dr. Perkin-its parent-has consented to sketch the tion with each other. Proust, in the course of essa history of its development. In this manner it is hoped troversy with Berthollet as to the fixedness of copy to impart considerable "local colour" to the Hofmann proportions, had observed that in certain cases i ** memorial lecture, thereby distinguishing it from the that in different compounds, consisting of the game notice which is being prepared by the German bio stituents, for a fixed quantity of one constituer graphers.

different quantities of another constituent bear Passing now to Prof. Mallet's lecture on Stas, which is other a simple multiple or sub-multiple rela:106 of considerable length, as it will occupy fully sixty pages Dalton, however, belongs the honour of announce in the Society's Journal. The biographical portion is l principle as a general one, and of basing upon it brief, as a number of such sketches have already been chemical atomic theory of the nature of matter. Bec

e early years of the present century, with apparatus The great majority of chemists—Prof. Mallet remarksany respects inferior to that of the present day, and at the present day, are probably agreed in believing that

scarcely any aid from chemical manufacturers in the hypothesis of Prout has been shown by Stas to be uring pure materials and reagents, but with unsur- untenable. But the fact that so many well determined d manipulative skill and the most honest criticism atomic weights, referred to hydrogen as unity present s own work, produced the first fairly trustworthy numbers nearly approaching integers, is very striking and f numbers representing the proportions by weight calls for further investigation. Stas himself is quoted as hich the elements combine. Berzelius began work admitting this much. Prof. Dewar, in the course of the is direction in 1807, his attention having been discussion after the paper was read, drew special attented by Richter's investigations; but soon after- tion to this question and gave several most striking s he became acquainted with Dalton's new atomic instances of the nearer approach to whole numbers which y of the nature of combination, and appears to have resulted from a recalculation of the accepted values, using impressed with its great importance, and at the the lower value for oxygen (15.87) which so many recent time with the need of more exact experimental researches tend to support, although on the other hand, for its support and development. The wonderful of course, some of the values now near to whole numbers acy of Berzelius's work generally is illustrated, as are considerably thrown out. Evidently there is ample Mallet points out, by the fact that his number for opportunity for further experimental investigation of this en, 16'021, becomes 15.894, almost exactly agreeing | all-important problem, and it is impossible-- notwiththe latest determinations of the present day, if the standing the extraordinary degree of accuracy attained hings of Dulong and Berzelius's three experiments on by Stas-to formulate any final conclusion. The supreme synthesis of water be corrected for the buoyancy | interest attaching to the problem was clearly recognised je air. Since Berzelius many other chemists have by Stas himself, as the following words show :ed in the same field, but his most worthy successor " Au point de vue de la philosophie naturelle, la ch labours has undoubtedly been Stas. With greatly portée de l'idée de Prout est immense. Les éléments r resources in the way both of apparatus and material, des corps composés que nous considérons comme des equal earnestness in seeking for the truth, with corps simples en égard à leur immutabilité absolue Tintelligence and skill he took up the task which pour nous, ne seraient eux-mêmes que des corps comme that of the largest part of his scientific life, and posés. Ces éléments, dont la découverte fait la gloire I more limited list of elements than Berzelius had de Lavoisier et a immortalisé son nom peuvent être itigated, produced results of a degree of accuracy | considérés ainsi comme dérivant de la condensation d'une h it is high praise to say would have delighted no matière unique : nous sommes naturellement conduits à more than Berzelius himself. He aimed at the de l'unité de la matière, quoi qu'en realité nous constations ination with greater precision than any one before sa pluralité, sa multiplicité." had attained of the atomic weights of some ten or This quotation is almost alone sufficient to show that re of the elements. But by so determining these Stas was a philosophical chemist of the highest order, ants he endeavoured also to settle several general and not a mere mechanical worker, as has sometimes tions of fundamental importance in regard to matter been supposed ; his unwearied attention to minutest idied by the chemist.

details has undoubtedly served to completely overshadow ius it has generally been assumed as true beyond the philosophical motives and aspirations by which he was ite since the early part of the present century, that guided. mass of an atom of a given element is a constant Stas also endeavoured to obtain evidence with regard tity. This has, however, occasionally been doubted, to the possible dissociation of the elements at high Stas himself considered the question as one requiring temperatures and to this end purified his materials with ination. His researches, however, lend no support every imaginable precaution. The skill with which he

On this point Prof. Mallet expresses himself carried out his operations is attested by the statement igly in favour of the orthodox view.

made by Mr. Crookes,the chairman at the reading of Prof. isuming that the atomic weights are immutable values, Mallet's paper, that he had seen in Stas's laboratory a large question arises, Are they commensurable ? This is mass of potassium chloride, which Stas had been years much-discussed hypothesis of Prout, the origin and in preparing, and in which he had failed to find a trace lopment of which is very fully discussed by Prof. of sodium even spectroscopically-such an achievement et. A widespread feeling at one time undoubtedly appears almost inconceivable to the chemist. Stas, in ed among chemists that Prout's hypothesis, that the fact, in the course of his work investigated the methods ic weights of the other elements are integer mul- of analysis to be used with a degree of rigour, and dis1 of that of hydrogen, if not true in its original form covered and applied refinements upon older methods of 1 ultimately prove to be so at least in a modified | experiment with a degree of patience and skill, such as

That Stas began his work under the influence of had never before been used in chemical investigation. eeling is clear from his own words :

Only those who are thoroughly conversant with such e le dis hautement lorsque j'ai entrepris mes re- / work can fully appreciate his labours ; they probably hes, j'avais une confiance presque absolue dans will agree that owing to the multitude and diversity of the titude du principe de Prout."

precautions to be taken, his work is the most difficult this experimental results clearly contradicted the hitherto attempted, and that he stands unsurpassed hesis, and he satisfied himself that the atomic among all who have undertaken the execution of exact its of the elements which he determined with such physical measurements. sion could not with truth be represented by integer A lengthy section of Prof. Mallet's paper is devoted to ples of the atomic weight of hydrogen, or the half the consideration of the objects to be aimed at and the fourth of this unit. In his own words :

methods to be pursued in future work. He advocates ussi longtemps que, pour l'établissement des lois the repetition by competent hands of some one at least gissent la matière on veut s'en tenir l'expérience, of Stas's fundamental results, calling attention to Stas's oit considérer la loi de Prout comme une pure own emphatic expression of the wish that this should be on. La simplicité de rapport de poids que pré- | done. It is also most important that no distinction ise l'hypothèse de Prout entre les masses qui should be made between rare and common elements, and iennent dans l'action chimique, ne s'observe donc that the atomic weights of all should be determined with

dans l'expérience; elle n'existe point dans la the least possible delay and the highest attainable degree é des choses."

of accuracy. Certain of the elements particularly call. for a more searching and exact investigation of their far too commonly disregarded by chemists. We atomic masses, e.g. elements such as tellurium, which now clear conceptions of atoms having constant occupies a position in the periodic system not in harmony for the same element, of determinable difference of me with its atomic mass, and cobalt, which plainly occupies in the case of different elements, the several masses the intermediate position between iron and nickel, and numbers of which regulate the composition of all km therefore should be intermediate in atomic mass.

substances and the products resulting from interior. In a number of cases the accepted value is based on among them. The atomic theory has advanced the investigation of but a single interchange, the value / beyond the condition of a mere working hypothes for iron, for instance, being practically based on the which chemists long stood with more or less uncerte results obtained on converting the metal into ferric oxide, feet; but even if this were not so, considering it, toe and vice-versa; and the relation of hydrogen to oxygen a common metaphor, only as a scaffold, there is no pa having been established by the reduction of cupric reason, so long as we stand on it and work from it, a oxide. It is desirable that in such cases other and in: we should be careless about tying our scaffold-pols a dependent methods should be resorted to, e.g. that nailing our planks. oxides of a number of metals other than copper should Lastly, Prof. Mallet urges that all atomic masses sibi be reduced, with the object of detecting possible constant be expressed in terms of the mass of the hydrogen an errors.

taken as unity, objecting strongly to the change to U=2 It is eminently desirable that an attempt be made to which several writers have recently advocated, the man directly determine the ratio of hydrogen to each of the objectionable argument put forward in favour of halogens without in any way bringing in the atomic mass change being, he thinks, that the numbers we x 2 of oxygen. Prof. Mallet suggests various methods deserv- expressive of ratios only—that any figures are 3 ing of study. Also it is very important that the metals able which correctly express combining ratios, and is of the yttrium and didymium groups should be further there are no reasons for using one set of figures 12 investigated. Prof. Mallet rightly terms the yttrium than another save mere arithmetical convenience 11 group the opprobrium of inorganic chemistry.

involves a grave error, as in adopting as unity tbe 35 Nearly all that has been written hitherto in regard to i of a single atom of any particular element, preferat the periodic relationship among the elements has involved that one of which the mass is the smallest, we z the use of roughly approximate values only ; but it is time reason to believe that we express the mass of alal that the foundation be laid for a more minute and critical others in terms of this as a really existent, dein study of the periodic system of classification. Anomalies and constant quantity of matter. It is, indeed, di in the classification as we now find it in our books, to understand when the scientific necessity in so sr glimpses of more detailed relations than as yet clearly cases of taking hydrogen as the unit is realized, appear, tantalizing suggestiveness in so much of what the change to 0 = 16 can be advocated except and is already before us, call for more precise determinations simple utilitarian plea that it is to the analyst's CONTE of the numbers we would discuss before we allow pre-ence. mature discussion to drift into mere fanciful speculation. Prof. Mallet's monograph is undoubtedly a mois

In regard to the methods which it is desirable shall be mirable exposition of the philosophical lessons : pursued in the determination of atomic masses, Prof. | learnt from the contemplation of Stas's labours. Mallet has much to say. He discusses the selection of processes, the purity of materials, the very numerous directions in which vigilance must be exercised in order to avoid extraneous or accidental causes of error, the

EXTINCT MONSTERS.1 quantities of material to be used, the practical precautions THE volume with this title treats of large animals to be observed so as to secure accuracy of manipulation 1 is clearly and simply written, without any press and in weighing and measuring, the mode of stating at being scientific, and is an excellent book for boys a. and calculating results, finally calling attention to the unlearned people who are curious to be informed upse advantage to be derived from the application of greater subject of fossil animals. It would have escaped crites working force and ampler means than can be commanded

altogether but for emphatic words of praise in the prec by private individuals to the determination of atomic and one or two passages in which the author, with seca masses ; with reference to this last point, during the i hand information, speaks authoritatively of predeces discussion on the paper, the opinion was freely expressed who restored extinct types of life with the slender man that it was undesirable that such work should be carried which were available forty years ago. The attract) out in organized public or semi-public laboratories. the volume and its novelty is a series of restoran The question is, no doubt, a difficult one to settle saurians and mammals drawn chiefly by Mr. Smit. 1 such work demands a special temperament combined for the most part are based upon the restorat:35 with genius of a high order and an infinite capacity | skeletons made by Prof. Marsh, whose discoveries a for taking pains, qualities which must rarely occur inspired Mr. Smit's pencil as much as they have united in a single individual. Moreover, in order that fluenced the author's pen. There is not much 222 the value of a result may be appraised, it is essential to beneath the skins of the « Monsters." and they hari overlook every detail involved in the determination. | aspect as though cotton-wool had taken the pa Given the man, however, there can be no longer a doubt / muscle, or as though the drawings were models far that every possible assistance he may require should “ Lowther Arcade. This, however, is of less impa be afforded him. It is marvellous that men like than the answer given to the question, Are they Berzelius and Stas, working all but alone and unaided, ably faithful to nature? It does not seem 10 should have achieved results of such magnitude and they can claim this merit; they are only reas universal importance--the moral effect of their example faithful to Marsh. Prof. Marsh draws an animas is certainly not less important than are the actual

| to give one type the maximum height to which the results of their labour.

can be hoisted; while another is given the man The last section of Prof. Mallet's paper is devoted | length to which the remains can be extended. to the discussion of the form in which it is desirable studies would not have led me to reconstruct 31 finally to state the results. He here advocates the uni- the extinct reptiles upon the lines which are adopte form substitution of the expression “atomic mass” for “atomic weight," on the ground that precision in lan

!"Extinct Monsters." A popular account of some of the large

ancient animal life. By Rev. H. N. Hutchinson, B.A, F.GS, guage conduces to precision in thought-an aphorism trations by J. Smit and others. (London : Chap nan and Hall,

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