the vessel-length over all, 785 feet; length between perpendiculars, 760 feet; beam, extreme, 88 feet; depth, moulded, 60 feet 6 inches; gross tonnage, 33,200 tons; net tonnage, 11,900 tons; maximum draught, 37 feet; displacement at this draught, 43,000 tons. The Mauretania is 160 feet longer than the Campania, of 1893, 78 feet 6 inches longer than the fastest of existing ships-the Kaiser Wilhelm II-and So feet longer than the Great Eastern, the greatest of preceding vessels.

Is Cornwall at the present time, owing to the high price of metals, there is great activity in copper and tin mining, and it is interesting to note, in an important article in the Times of September 17, the extent to which scientific methods and the latest improvements in appliances are being adopted at the newly started mines. haile mine, for example, with the aid of a gas-power plant and electric pumps, the workings have been drained at the rate of 1400 gallons a minute. This speed has never been approached in the past history of Cornish mines. At the Great Dowgas tin mines, pneumatic stamps will for the first time be driven direct by gas power, and winding and pumping will be electrical. At the Alfred mines a central gas-power plant has also been installed. When work was resumed at the Clitters mine some five years ago, those responsible formed the opinion that the costs of working mines in Cornwall were far too high; that values existed in mixed ores far beyond the knowledge of those then concerned in mining and dressing such ores; and that great improvements in mining and dressing methods were possible. It has been proved that these impressions were true, and future developments in the application of modern scientific methods to the ancient Cornish mines cannot fail to be watched with interest.

THE seventeenth annual general meeting of the Institution of Mining Engineers, held at Hanley on September 12-14 under the presidency of Sir Lees Knowles, was very largely attended, and an interesting programme of visits and excursions was arranged. The report of the council showed that the membership of the institution now amounts to 3034. Mr. Maurice Deacon (Chesterfield) was elected president for the ensuing year. Three papers were read. Mr. W. D. Verschoyle described a new pocket transit, which was really a combined prismatic compass and clinometer, ingeniously arranged for observing very steep angles. Mr. T. Trafford Wynne gave a detailed description of the gypsum deposits of the Dove Valley. The discussion on this paper was well sustained. Mr. Bennett H. Brough pointed out that the author in his introductory sketch of the occurrence of gypsum had omitted to refer to the Paris deposits, which produced two-thirds of the world's supply. The speaker suggested that there was considerable room for improvement in the manufacture of plaster of Paris. Scientific progress had hardly touched the technology of this material, and the temperature of burning and the degree of fineness received no attention. The methods of testing gypsum were now to be investigated by a committee of the International Testing Congress. The charge of want of progress was warmly combated by other speakers, who adduced evidence to show the high degree of scientific method followed in several plaster works in this country. In conclusion, a paper was read by Mr. E. B. Wain and Mr. J. T. Stobbs on the Cauldon Low and Manifold Valley, North Staffordshire, a district of considerable geological interest, in which a large quarry of Carboniferous limestone of very pure quality is worked, and where at one time the famous Ecton copper mine was of great importance.

IN the Indian Forester (July) the editorial article bears testimony to the foresight of the present Commander-inChief in India in demanding the preparation of working plans for cantonment forests in India, and summarises a similar scheme drafted by the United States Forest Service for the Military Department for a forest reservation at the military academy army post at West Point, New York. Following on previous references to types of forest resthouses in India, Mr. E. P. Stebbing deals with those met with in Assam, that from descriptions and illustrations are no more satisfactory than those provided in Burma.

WITH reference to the maintenance of the Imperial Department of Agriculture in the West Indies, an editorial notice appears in Tropical Life on the work of botanical and experimental stations. It is appropriate to find in the same number a biography of Dr. J. C. Willis, who has done so much towards bringing the agricultural community in Ceylon into its present prosperous condition. A note on the camphor industry contains a description of the Formosan method of distillation, and the opinion is expressed that the present price of camphor could be reduced to one-third or less before the Formosan monopoly would be endangered.

THE Museums Journal for August is entirely occupied with the report of the recent conference at Bristol and an illustrated account and history of the museum buildings of that city. In the latter, the development of the museum and art-gallery is carefully recorded by Mr. W. R. Bacher during a period approaching a century and a half—17721906. It is well known that the Bristol Museum possesses a number of natural history treasures, among them an example of the typical southern race of the bonte-quagga, or Burchell's zebra, now apparently extinct, and unrepresented in the national collection.

IN the twenty-first Educational Leaflet, dealing with the scarlet tanager, the U.S. National Association of Audubon Societies (as represented by its president, Mr. W. Dutcher) strikes an important note in asserting that its objects are not limited to the protection of birds, but embrace the awakening of an interest on the part of the agriculturist (as well as the student) in bird-life generally. Undoubtedly this is the right way of looking at the subject, and if it were inculcated and adopted in this country (together with some relaxation of the law in regard to species held to be harmful by practical people), we should probably hear fewer objections to bird protection. The coloured plate shows the male and female tanagers in their respective

HOLMES'S COMET (1906).-In No. 4121 of the Astronomische Nachrichten Prof. Max Wolf states that he has measured the position of Holmes's comet on the plate secured on August 28. He gives the exact position, for 1906-0, at the time of discovery, and this shows that corrections of +6-79s. and +28"-2 are necessary to Dr. Zwiers's ephemeris. As the comet is extremely faint, mag. = 15.5, a continuation of the ephemeris is not given here, but will be found in No. 4085 of the Astronomische Nachrichten.

OBSERVATIONS OF SOLAR PHENOMENA, 1906.-The results of the observations of sun-spots, faculæ, and prominences made during the first semester of the present year at the Catania Observatory are published by Prof. Mascari in No. 8, vol. xxxv., of the Memorie della Società degli Spettroscopisti Italiani.

The mean daily frequency of spots was higher during the second than during the first quarter, the respective numbers being 5-68 and 4-50; the faculæ behaved similarly. For prominences the reverse was the case, there being a mean daily frequency of 4-38 prominences during the first quarter and 3.47 during the second. Discussing the results in relation to the time of the solar maximum, Prof. Mascari places the epoch of maximum spots at 1905-2, and that of faculæ and prominences in the last quarter of 1905 or the first quarter of 1906.

OBSERVATIONS OF JUPITER.-The observations of Jupiter made by Mr. Denning during the last opposition showed that the rotation period of the Great Red Spot and its Hollow, in the south equatorial belt, between March 24 and May 4. was 9h. 55m. 40-6s., a period practically conformable with that of system ii. of the ephemerides. On observing the phenomena on August 9, however, he found that they were far in advance of their predicted places, an observation confirmed by the Rev. T. E. R. Phillips. From this it appears that the rotation period between May 4 and August 8 was only oh. 55m. 33-8s. Mr. Denning supposes that the conjunction of the dark material, forming the south tropical disturbance, with the Red Spot, in June last, may have caused the marked acceleration of the latter, as it has done on several former occasions. The present increase of velocity is, however, much greater than any previously observed, and these features appear to have been observable for seventy-five years (the Observatory, No. 374).

In the September number of the Bulletin de la Société astronomique de France M. Flammarion directs attention to a remarkably sudden change in the visibility of the north equatorial band on Jupiter. This band has been diminishing since the end of 1903, and an observation made by M. Benoit, at Juvisy, on April 10, 1906, showed that it was almost completely invisible. After its conjunction with the sun, Jupiter was observed again on July 17 by M. Quenisset, who was astonished to find that the north equatorial band was completely reformed, being even broader, and at some points darker, than the south equatorial band. A drawing, made by M. Quenisset on July 23, is reproduced with the article.

THE KODAIKANAL OBSERVATORY.-An interesting popular account of India's solar physics observatory, situated at Kodaikanal, on the Palani Hills, appears in the July number of the Madras Christian College Magazine. Mr. Monteith Macphail, the writer of the account, lately visited the observatory, and was evidently impressed with its situation and its work. The altitude of the observatory is about 7700 feet, in an atmosphere of exceptional transparency, and amid beautiful surroundings.

Although located in Madras, the institution was founded, and is supported, by the Government of India, thus having a national and not merely a provincial status. Its chief raison d'être is the continuous study of the sun, with the ultimate idea of elucidating still further the indicated relationships between solar and terrestrial atmospheric phenomena. To a country like India, the value of possessing the fullest possible knowledge of these relationships cannot be overestimated, and that is the reason why the Government of India has seen fit to found and to support this observatory and its equipment in the most favourable situation at its command. Sun-spots, their spectra, and prominences on the solar limb, are observed visually,

and spectroheliograms of the solar disc and limb are taken on every day on which the atmospheric conditions are suitable. Magnetical and seismological records are also

taken.

CHEMISTRY AT THE BRITISH
ASSOCIATION.

IT was somewhat noticeable that the trend of the proceedings in Section B this year was in the direction of applied chemistry; general problems on the theoretical side of the science came under discussion in Section A; if this indicate either that this section is becoming alive to the importance of chemistry to physics or a rapprochement of the two sections, it is a good sign, but it is not satisfactory if it mean the neglect of broad considerations by the chemist.

Reports were presented by Mr. S. S. Pickles, on the chemistry of rubber; on that of gums, by Mr. H. H. Robinson; and on the hydrolysis of sugars, by Mr. R. J. Caldwell. These gave rise to more or less interesting discussions and were a valuable feature of the meeting. Discussion also centred round a paper by Dr. T. A. Henry, on the production of hydrogen cyanide in plants. The was of joint discussion with the physiologists on diet great interest, although it was mainly developed in physiological and sociological directions.

The proceedings opened on the Thursday, August 2, with an important paper by Messrs. S. Leetham and Wm. Cramp, who have been engaged in perfecting an apparatus for the production of an active mixture of gases which may be used for bleaching and sterilising purposes, particularly in bleaching flour. The apparatus consists of an alternator, transformer, ozoniser and spark box, the two latter being in series on the high-tension side of the transformer; on passing a current of air through the ozoniser and then through the spark box a gaseous mixture is produced, containing minute amounts of ozone and oxides of nitrogen, which has a very remarkable bleaching and sterilising action on flour; the process is already one of considerable commercial value. The bleaching action

appears to be an oxidation effect.

The authors have studied in great detail the behaviour of the different types of electric discharge and the influence of such factors as the number and distance apart of the discharge points, shape of the points, the air velocity and the frequency. The conclusion arrived at is that ozonisation is not a mere induction effect. In commenting on the paper, Prof. Armstrong dwelt on the importance of manufacturers taking interest in science, and referred to the work as an illustration of the advantages of such co

operation.

Following a short paper by Prof. van Romburgh, of Utrecht, on the 1:3: 5-hexatrien, reports were read of the committees on dynamic isomerism, on hydro-aromatic substances and on aromatic nitro-amines. The rest of the morning was devoted to inorganic chemistry, papers being contributed by Mr. A. Vernon Harcourt, on the effect upon the concentration of a solution of the presence of an excess of undissolved salt; by Mr. G. Beilby, on the crystallisation of gold in the solid state; and by Prof. H. A. Miers and Miss F. Isaac, on the temperature at which water freezes in sealed tubes; this is found to be very considerably below that at which solidification takes place in open vessels.

The greater part of Friday, August 3, was devoted to a discussion on the production of hydrogen cyanide in plants, introduced by Prof. Dunstan, who pointed out that in the case of both Lotus arabicus and Sorghum vulgare the cyanide was formed only during the early stages of growth, and that it was missing in the mature plant. The fullygrown Lotus vetch is much used as a fodder plant in the Nile valley, but many fatal cases of poisoning have been caused through its use in the immature state. Hydrogen cyanide has also been detected in Java beans, of which there are several varieties; the maximum amount is found in the dark beans, and it is only safe to use the light bean. In the flax plant, which also affords hydrogen cyanide, the maximum amount is produced at an inter

526

mediate stage when the plant is from high.

inches to 5 inches

Dr. Henry followed with an account of the glucosides containing the hydrogen cyanide, which have been grouped together as cyanogenetic glucosides. They are allied to amygdalin, the active principle in bitter almonds, which is therefore the oldest known representative of the group. The list at present comprises, besides amygdalin, sambunigrin, prulaurasin and a glucoside, prepared artificially from amygdalin by Fischer, known as mandelnitrileglucoside, all of which are resolved by acids into glucose, benzaldehyde and hydrogen cyanide; further, dhurrin, phaseolunatin, lotusin and gynocardin.

The plants containing these glucosides also contain enzymes, which resolve them-when the plant is macerated with water-into hydrogen cyanide, glucose and a third constituent. The question was raised as to the role of the hydrogen cyanide, whether it acted protectively or whether it played a part in the production of proteid from nitrates. Dr. Greshoff, of Harlem, dealt with the question from the botanical side, and put forward a list of all the species of plants known to yield hydrogen cyanide, which will be of great value to future workers.

A paper on the utilisation of atmospheric nitrogen by plants, read by Mr. Thomas Jamieson, described what the author regarded as special organs in plants adapted for the direct absorption and assimilation of nitrogen from the air. His conclusions were most severely criticised by Prof. Potter from the botanical side, and by Mr. A. D. Hall and others.

The report on caoutchouc, presented by Mr. S. S. Pickles, contained a general survey of the chemistry of this remarkable product.

con

stituents of Dyera Costulata.

were C02

not

Attention was directed by Dr. Hopkins--and this point was particularly emphasised by Prof. Armstrong-that it was not justifiable to consider merely the gross amount of taken into account. Thus, for example, wheat is probably protein, but that the nature of the protein had also to he the best form of protein, its main constituent, glutaminic acid, being, so far as our present knowledge goes, of relatively little value as a tissue former compar with other amino-acids. Maize protein is perhaps of even lower value, whereas rice and oats, among the cereals, appear to be the especially valuable sources of protein. Prof. Armstrong particularly referred to the need of making detailed study of foodstuffs, our present method of referring to the nitrogen content generally multiplied by a factor as protein giving no true guide as to the relative value of foods, inasmuch as protein is a highly complex material, made of ever-varying units, the nutritive value of which taken singly varies within wide limits.

The rest of the morning was devoted to agricultural chemistry, Messrs. A. D. Hall and C. T. Gimingham contributing a paper on the action of ammonium salts upon clay and kindred substances, following which Dr. E J. Russell read a communication by Dr. F. V. Darbishire and himself on oxidation in soils and its relation to proan apparatus ductiveness. These authors have devised

for measuring the rate of absorption of oxygen; the power of absorbing this gas possessed by all soils appears to be due mainly, though not entirely, to the activity of microorganisms. The rate of oxidation does not entirely depend on the amount of organic matter present in the soil: moisture is essential, and as it increases so also does the rate of oxidation. The rate is also increased by the addiFor a series of tion of calcium carbonate or of sugar. similar soils, of which the cropping power is known, it s found that the most productive has the highest rate of oxidation, and that the others follow in the same order for both properties. The parallelism holds also for soils which have been artificially treated; it is essential however, that the soil conditions should be aerobic. the rate of oxidation affords a authors suggest that measure of the bacterial activity, which is closely connected with productiveness.

The

The last paper read was by Mr. W. Popplewell Bloxam, on a new method of determining indigotin. After pointing out the need of a method of controlling the still ver crude processes in vogue for extracting indigo, and the importance of determining the daily yield of indigotin obtained in an ordinary factory from known weights of green plant, the existing methods of analysis were discussed and the uncertainty of the results they afford alluded to. In the author's method, the indigotin is with fuming sulphuric aud sulphonated by treatment (containing 20 per cent. sulphur trioxide); the solution is then diluted, and the potassium salt of indigotin tetrasulphonate precipitated by means of potassium acetate Finally, the amount of indigotin in the salt is estimated by titration with potassium permanganate or titanium chloride. The author concludes that the present process of manufacture is wasteful one, the highest efficiency attained not reaching 50 per cent., whilst on the average only 25 per cent. of the indigotin in the leaves is extracted.

a