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THE MANUFACTURE OF CYANIDES. The Cyanide Industry Theoretically and Practically Considered. By R. Robine and M. Lenglen. Translated by J. Arthur Leclerc, Ph.D., with an appendix by C. E. Munroe, Ph.D. Pp. xix 408; illustrated. (New York: John Wiley and Sons; London: Chapman and Hall, Ltd., 1906.) Price

173. net.

THE

HE stimulating effect on industrial research caused by the prospect of immediate material gain is strikingly illustrated by the progress of the cyanide industry. Until cyanide of potassium was applied to the treatment of gold ores, comparatively little interest was taken in its manufacture. The consumption amounted to about fifty tons a year only, and the old expensive and wasteful methods of obtaining it from ferrocyanide which had been made by the use of nitrogenous organic substances were deemed sufficient for the purpose. When the demand was rapidly growing in the nineties there was a rush of investigators to discover new and cheaper methods of manufacture. A fair amount of success was attained, and some thousands of tons of cyanide are now produced annually in Great Britain and Germany and sold at one-third the former price. The older processes have been abandoned and new ones introduced, and, although some doubt still remains as to the future of the industry, the field for useful research has been narrowed, and once again offers little attraction to the chemical" pot-hunter." Comparatively little cyanide is produced in France, however, and apparently it was the apathy of their fellow-countrymen on the subiect which induced MM. Robine and Lenglen to write the book which has just been translated.

It con

The authors divide their book into four parts, of which part iii., on the methods of manufacturing cyanide compounds, is alone of any real importance. Part i., occupying sixty-five pages, deals with the chemistry of cyanogen and its derivatives. tains no correct statement that does not appear in ordinary text-books of chemistry, and is distinguished by an extraordinary number of misprints or misstatements, such as "cyanogen does not unite directly with hydrogen," "it [cyanogen] becomes a liquid at 20°.7 under ordinary pressure," and "If the cyanide contains chlorides, the method [of estimation of cyanide by means of silver nitrate] is not accurate." There are no references to the sources of information, and the whole section seems to have been drawn up in a perfunctory way.

Of even less value is part ii., which occupies twelve pages, and is on "The Present Condition of the Cyanide Industry." None of the information given in this part appears to be of later date than 1901, and some of the tables of figures end in 1896. The tables refer mainly to France, but there is a list of works producing cyanide compounds which applies to the whole world.

Part iii. occupies 213 pages, and gives a clear account of a very large number of methods of manufacture, most of which, as the authors are careful to point out, have never been successful on an in

dustrial scale. All the chief cyanide compounds are dealt with, and separate chapters are devoted to the manufacture of cyanides, ferrocyanides, ferricyanides, and sulphocyanides. Sulphocyanides and, to a less extent, ferrocyanides owe their importance to their use in the preparation of cyanides, but the authors devote most attention to the interesting direct synthetic processes of making cyanides from carbon and nitrogen or ammonia.

The fixation of atmospheric nitrogen is a fascinating problem which is likely to continue to exercise the minds of chemists, and the translator, as an agricultural chemist, expresses the daring hope that the publication of this volume will result in the solution of the problem on an industrial scale. It is, of course, well known that cyanides are formed in blast furnaces, and many attempts have been made to apply this knowledge, beginning with Bunsen's special furnace, which was built in 1845. In most of the later processes, atmospheric nitrogen, freed from oxygen by passing it over heated metals or by distilling liquid air, has been passed over carbides of metals heated in electric or other furnaces, but although some progress has been made, the cyanide industry still continues to depend on more roundabout chemical actions. One of these is the synthesis. of sulphocyanide by the action of ammonia on carbon bisulphide in the presence of a base such as lime, fol-lowed by the reduction of the sulphocyanide by means of carbon, metals, or hydrocarbons.

Illuminating gas and its residues constitute a source of cyanide which has not been fully exploited. The authors anticipate that in the future a large proportion of the required cyanides will be obtained from gas works, and estimate that in France alone. 4,000,000 tons of coal used annually in the manufacture of illuminating gas could be made to yield cyanide compounds worth from eight to twelve million francs, all of which is now lost. In other countries, however, the matter has not been overlooked, and it is certain that the illuminating gas. used in the world could be made to yield far more cyanide than could possibly be disposed of, unless new uses for cyanide should be discovered. The pro-gress of the cyanide industry is checked rather by well-founded fears of overstocking the market than by the neglect by manufacturers of their opportunities. or by the need of fresh sources of supply.

In part iv., which occupies twenty-seven pages,. there is an adequate account of the use of cyanogen compounds, and this is followed by an appendix of seventy-one pages. Here a digest is given of the United States patents relating to cyanide processes for the recovery of the precious metals. No doubt the list is fairly complete, but it has nothing to do with the main subject of the book, and does not contain any reference to patents relating to the manufactureof cyanides. However, as it shows the activity of the consumers of cyanide, it may be taken as a tonic by disheartened manufacturers, who, after all, are probably more interested in markets than in chemical formulas. T. K. ROSE.

A YEAR ON THE "SIBOGA.” Ein Jahr an Bord I.M.S. Siboga. Von Frau A. Weber van Bosse. Beschriebung der Holländischen Tiefsee-Expedition im Niederländisch-Indischen Archipel 1899-1900. Nach der II Auflage aus dem Holländischen übertragen von Frau E. Ruge-Baenziger. Pp. xiii+370. (Leipzig: W. Engelmann, 1905.) Price 6s. net.

IN

N this book Mrs. Weber gives a popular account of the expedition the scientific results of which have been described in the " Siboga-Expeditie " edited by Dr. Max Weber.

The Siboga, a twin-screw vessel of the Royal Dutch Navy, built for the East Indian service, deprived of her armament, and specially fitted for her scientific voyage, left Surabaya, on the north coast of Java, on March 7, 1899, and returned thither on February 26, 1900, having spent the interval-practically a year -in exploring the marine, and especially the deepwater, fauna of the East Indies. The expedition consisted of Prof. Max Weber and Mrs. Weber, two scientific assistants, a doctor, and a draughtsman, and received from the naval staff of the vessel those ungrudging and invaluable services which the officers of our own Navy so invariably put at the disposal of the scientific members of an expedition. The investigation of the marine flora was in the hands of Mrs. Weber.

The course of the Siboga lay at first along the coasts of the Lesser Sunda group from Java to Timor, then across the Flores Sea to Saleyer Island, and to Macassar, in Celebes, where the expedition was landed for a time while the ship made a trip to Surabaya. On her return the voyage was continued through the Macassar Straits to the Sulu Islands, then southwards across the Celebes Sea to Kwandang, in Celebes, northwards again to the Sangir and Talaur groups, southwards through the Molucca Straits to Obi, and eastwards across the Halmahera Sea to the coast of New Guinea. From Atjatuning, in New Guinea, the ship sailed by Ceram, Amboyna, Buru, and Buton to Saleyer again. Here the expedition was left during a second trip of the Siboga to Surabaya. When a fresh start was made the course lay eastward across the Banda Sea by Amboyna to Aru and back to Amboyna. From this place the Siboga returned to Surabaya along the Sunda Islands by a different route from that which she had taken at starting.

The story of this voyage is pleasantly told by Mrs. Weber. Scattered through her account of the everyday life of the ship and the happenings at various stopping-places and dredging-grounds are allusions to the scientific discoveries of the expedition. Some of the soundings are particularly interesting. It appears that the Lombok Straits, instead of being a deep cleft between Bali and Lombok, are in reality quite shallow (170 fathoms). Since Weber has already shown that the fauna of the East Indies changes only gradually from an Asiatic to an Australian character in an easterly direction, we have now probably heard the last of that old friend of our

student days, "Wallace's Line ❞—a picturesque and fruitful hypothesis, for all the contempt with which it is apt to be treated nowadays. On the other hand, interesting soundings of considerable depth were obtained among the islands-some 2700 fathoms in the Banda Sea and in the Celebes Sea, 2200 fathoms in the Ceram Sea, 1500 fathoms between the Banda Sea and the Flores Sea, and 2000 fathoms close to land off Saleyer. Near the latter island great banks of calcareous algæ were found, which recalls Stanley Gardiner's observations on the importance of these organisms in Funafuti and elsewhere. The plankton also seems to have been unusually rich and plentiful. The sea bottom is in many places rough, entirely unlike the oozy bed of the great oceans, and was the cause of much loss and damage to gear.

The book is well got up and illustrated by some good photographs, and should prove interesting to the large class of readers who are attracted by books of travel.

YORKSHIRE FUNGI.

The Fungus Flora of Yorkshire. By G. Massee and C. Crossland. Yorkshire Naturalists' Union Botanical Transactions, vol. iv. Pp. 396. (London: A. Brown and Sons, Ltd., 1905.)

HE Yorkshire Naturalists' Union has held and THE maintained a high place in the history of British cryptogams, and its published Transactions abound in records of fungi in which the county seems to be peculiarly rich. It is hardly surprising, therefore, that a scientific society of such well-proved eminence should every now and then issue the results of its labours, originally published in its serial journal, in the form of a separate book.

To do this in the case of the fungi required more initiative and enterprise than with most other cryptogams, and the committee is to be congratulated, not only on having carried the work through, since 1902, but on having done it so thoroughly and efficiently.

When we extend our congratulations also to the two authors responsible for the work, we may take the opportunity of pointing out that while one is an amateur field naturalist of that peculiarly enthusiastic and accurate type for which Yorkshire has long been famous, the other is a professional mycologist of high reputation; and the combined labours of the two give us all the advantages of the accurate and industrious notes of a collector who knows his county thoroughly, together with the critical supervision of one who knows his herbarium equally well, and who has had shed on to his shoulders the cloak of Berkeley, and has been a fellow-worker with Cooke.

The book consists of 365 pages with appendices and an index, a too meagre bibliography, and more than 2600 entries. There is a short introduction and classifica. tion, with notes on the distribution within the county. The work is by no means a mere catalogue, though in many cases little more than the record of the name is given, together with the localities in which the fungus has been found growing. Interesting notes

as to the habit of the fungus abound, and while it is, of course, impossible in such a work to define species or even genera, there are excellent explanatory notes here and there for the use of the critical systematist.

The volume, which is neatly printed, is, in spite of rather too many misprints, indispensable to every professional mycologist, and will, of course, be the basis for all other fungus floras of Yorkshire and other counties.

The work affords a very good example of the excellent services to science which may be contributed by the collaboration of individual workers who are experts in different departments and will join their forces loyally for the benefit of the rest.

Of course, it is not claimed that all the fungi of the large area covered are recorded, and much remains for other workers, especially in the domain of the smaller and lower fungi; but, as has already been pointed out, we have a firm basis for the benefit of further workers, and shall hope to see the records gradually rendered more and more complete.

OUR BOOK SHELF.

The Principles and Practice of Iron and Steel Manufacture. By Walter Macfarlane. Pp. xi+266; ob figures. (London: Longmans, Green and Co.) Price 38. 6d. net.

This is a difficult book to review so as adequately to represent the nature of its contents to the "technical students, metallurgists, engineers," and others for whom it is intended. The somewhat florid style of the introduction, "Machinery ponderous and powerful or nimbly delicate and deft. ." would lead one to expect a kind of poetic phantasy woven to give joy to the general reader, and the expectation is supported by the last sentence, about iron being the Master Metal because it has so many good qualities in well-balanced proportion. Really it is quite human, however, in that it has many wicked ways also, well known to the aforesaid engineers.

Later in the work there is a compound of the general and the technical, as is evidenced by the type of illustrations, numbering about a hundred, of which a considerable proportion are reproductions from photographs; thus, "Fig. 6. Charging a puddling furnace"; "Fig. 44. Siemens casting pit with ladle in the distance," evidently taken with a short-focus lens, for the ladle seems about half a mile away; "Fig. 54, Shovelling lime into

a

steel works, and is also very misleading to a student of the subject. The matter has been dealt with in recent and ancient literature.

To sum up, the work may be of considerable interest to the general reader, but can hardly be recommended as a guide to the technical man engaged in such work as the manufacture of steel.

On Models of Cubic Surfaces. By W. H. Blythe.
Pp. xii+ 106. (Cambridge: University Press, 1905.)
Price 4s. net.

MR. BLYTHE has attempted a difficult task, to give an
account of methods of constructing models of a cubic
surface without either assuming all the theory of the
surface as known or recapitulating it; the result, so
far as the introductory portions of the book are con-
cerned, is an unsatisfying mixture of rudiments and
quotations and references to difficult theorems. As
regards the latter portion Mr. Blythe may best speak
for himself. "About ten years ago my attention was
drawn to arranging the twenty-seven straight lines.
. . After constructing several models, I did not con-
tinue the series, for I subsequently found that a com-
plete set had been made in Germany.
Copies of
these models can be purchased. Still the models
described in this book are sufficient to give an idea of
the shape of a cubic surface."

We think Mr. Blythe is too modest, and that this little book of a hundred pages will be of interest to those who are studying the surface and desire actually to make models; but it must be confessed that in our opinion the writer would have been better advised either to make the theoretical portions more systematic or to have omitted them, and given a fuller account of the models with many more figures. Perhaps it is fair to say that Mr. Blythe's book is a good example of what may in cases be the bad effects of a too rigid and uniform examination system; it happens that cubic surfaces are outside what is regarded as the normal course of geometry for a student for the mathematical tripos; under a free and stimulating system, when Mr. Blythe first began to take an interest in models of cubic surfaces he would have been encouraged by his environment to go on and make a complete set, and other students would have helped him, and there would have been formed a fresh rootlet for the mathematical school to grow from; as it is, the environment requires either that he should invent a completely novel theory of the surfaces or models, or pav the penalty of being regarded as off the track, except by those few who value mathematics as they find it

interests them.

A

Synonymic Catalogue of Homoptera.

Part i. Cicadida. By W. L. Distant. Pp. 207. (London: Printed by Order of the Trustees of the British

MR. W. L. DISTANT has for many years made a study of the Rhynchota, and has paid particular attention to the Cicadida. The catalogue of this family, together with a synopsis of the subfamilies and genera now published, was, we learn from Prof. E. Ray Lankester's preface, generously placed at the disposal of the Trustees of the British Museum by Mr. Distant. This work should be of great assistance to students of this group of insects.

Museum, 1906.) steel melting furnace "; while "Fig. 52, Empty steel ladle," may be introduced to finish with a little humorous touch. Taking at random the working of an acid open-hearth charge, the author says that after melting (p. 117) "Oxidation steadily proceeds. In the first two stages the oxidation is effected by the excess air which enters the furnace along with the producer gas. The oxidised products SiO, MnO, and some FeO and Fe,0, go into the slag. In the third stage oxidation is largely due to the oxygen in the ore which is fed in." On p. 122 the author distinctly says, "During the third or boiling stage . . . when this stage is reached ore is cautiously fed into the furnace. . . How long it would take an ordinary charge to come on the boil without ore one could hardly guess, but to bring it on in a reasonable time requires very considerable additions of ore to get the slag into proper condition. This is a grave error for an author who has been fourteen years in iron and

Iona. By Elizabeth A. McHardy (Mrs. Raymond
Smith). Pp. 48. (Glasgow: R. Gibson and Sons,
Ltd., n.d.) Price 18. net.

THIS attractive booklet provides brightly written and
well illustrated accounts of Iona-" the Blessed Isle "

and of Staffa with its wonderful Fingal's Cave, together with an appreciation of St. Columba. It should not be long before the little publication secures a wide popularity among visitors to the west of Scotland.

LETTERS TO THE EDITOR.

[The Editor does not hold himself responsible for opinions expressed by his correspondents. Neither can he undertake to return, or to correspond with the writers of, rejected manuscripts intended for this or any other part of NATURE. No notice is taken of anonymous communications.]

Kew Publications.

As I was responsible before I left Kew for the publications noticed in NATURE of June 21 (p. 180), perhaps I may be permitted a few words of explanation.

The Kew Bulletin was not intended at the outset to rank with scientific journals. It was started at the desire of Parliament for the purpose of issuing, for public use, information for which there happened to be a demand, and of a commercial, or at any rate economic, kind. It was subsequently decided by the Government that it should be the vehicle for other matter, scientific or otherwise, for which prompt publication seemed desirable.

It is sent out to all the botanic and agricultural departments in correspondence with Kew in India and the colonies, and much of its contents is usually reprinted in the local journals.

It also serves the purpose of expeditiously answering inquiries at home. A stock of the numbers is kept at Kew for communication to correspondents. So useful has it proved in this way that it has been necessary to reprint more than once a large number of the articles. The output in any one year may have been exiguous; but if there was no urgent demand for information on some new subjects, there was usually more pressing work on hand than the mere manufacture of padding. As, however, the Bulletin is filed in many libraries, I was glad to have the leisure to put the successive annual volumes into a shipshape form. When the next general index is issued the whole series of volumes will form a sort of rough, though necessarily incomplete, encyclopædia of practical information on Indian and colonial agriculture and products.

The announcement of appointments may have been belated, but that again is of little consequence, as they are only intended to be items in a continuous record.

The catalogue of portraits was not supposed to be exhaustive, and does not compare, therefore, with the "Catalogus Stockholmiensis." It is simply a hand-list for the use of visitors of the portraits exhibited in Museum No. 1. The Kew collection has always been popular, and, as I know of no other, is " probably unique," but it has latterly grown out of all bounds. As the available space was restricted, I made a selection, and, so far as prints were concerned, had them uniformly framed. I was guided by considerations which I have stated in the preface, and I confess I was largely influenced for the purpose of public exhibition by artistic merit. Mere trivial photographs and cuttings from illustrated papers, though valuable so far as they go, seem to me most conveniently preserved in portfolios.

The personality of those who have made a mark in scientific history has, I think, a peculiar, because intimate, interest. The world is certainly the poorer for having no portrait of Gilbert White. Only recently I have seen the posthumous portraits of two distinguished men of whom no memorial now remains which bears the impress of vitality.

In the seventeenth and eighteenth centuries few me of any note disdained to transmit their portraiture to posterity by the aid of the engraver. It was not, indeed, until the middle of the last century that the practice expired in the more feeble art of the lithographer. Some examples of its decadence I felt obliged to withdraw as painful caricatures. Nowadays, modesty or indifference seems to leave neglected all but the most eminent. I am not without hopes that more space may be found at Kew for portraits. I hope the collection may continue, as in the past, to be the recipient of gifts from private liberality, and that in this way many obvious gaps may be filled up. W. T. THISELTON-Dyer.

Witcombe, Gloucester, June 25.

A Remarkable Lightning Discharge.

THE afternoon of Saturday last, June 23, was sultry, and it was therefore without surprise that about 8.30 p.m. we observed the reflection in the clouds of lightning to the west and south-west, and heard from time to time the low sounds of distant thunder; there was no indication of the storm coming near to us until 9.30 p.m., when we were startled by a tremendous explosion and a brilliant flash of light, which, according to some observers, was continued after the explosion took place. This explosion was, I think, the loudest that I ever heard, and the

impression on all of us was that it was quite close, and I am told that it was heard nearly two miles off as if it was close at hand. The thunderstorm continued for some hours after this explosion, but never came near to us.

It was not until the next morning that we discovered the scene of the explosion of the fire-ball, if such was the nature of the agent.

In one part of the garden here there is a mound-the remains of an old greenhouse-of irregular form and height on the northern side grown over with ferns, ivy, and weeds, from which, towards its western end, grows an ash tree of moderate size, which gives out its first branches between 16 feet and 17 feet from the ground. The leaves of the tree seem intact, but the ivy of the trunk, from immediately below the branches down to the mound, has been more or less stripped of its leaves; a space half round the tree has been disturbed, and the weeds and plants thrown down, very much as if they had been trampled down by human feet; and this disturbance is continued in a line down the mound on the northern side, the plants being depressed from above downwards, and the gravel path at the foot of the mound broken up more than halfway across. Many of the leaves of the ivy have been scattered about, and many of the leaves lying on the mound have been torn to pieces. Several pieces of dead wood on the mound have been broken asunder. A branch of ivy close to the root of the ash tree has been stripped of its bark; an old brick lying on the mound under the vegetation was broken into four pieces, two small pieces and two large of nearly equal size; one of these larger pieces was found on the mound, one was found about 7 feet 6 inches from the point at the foot of the mound where the disturbance was seen, one smaller piece was about 7 feet beyond this, and another yet 2 feet further beyond the last. A piece of highly-crystallised Old Red Sandstone lying on the mound was found with a new and unweathered exposure several inches in length, and fragments of the same stone with new faces were lying near.

The conclusion from these facts seems to me to be that the electric agent, whether a fire-ball or not, must have approached the ash tree in a nearly horizontal line and struck it just below the lowest branches, have passed down the tree to the mound, have disturbed the vegetation to the south of the trunk of the tree, have passed then towards the north down the mound, and then to have nearly crossed the garden path, when it disappeared When exactly the explosion took place I feel at a loss to ascertain, but perhaps some of your readers may be able to assist in determining this point. EDW. FRY.

Failand, near Bristol, June 25.

The Magnetic Inertia of a Charged Sphere in a Field of Electric Force.

DR. O. HEAVISIDE has investigated (NATURE, April 191 the slow motion of a charged conducting sphere through a uniform electric field, in a direction parallel to the electric force of the field, and has calculated the increase in the magnetic energy and inertia of the sphere resulting from the re-distribution of the charge under the influence of the field. His paper has suggested the following investigation, in which the slow motion of the sphere is at right angles to the direction of the electric field. But, as Dr. Heaviside has pointed out to me, this problem has no single definite solution. For, if the sphere, initially at rest in the field, be set in motion, the motion of the unequally distributed charges on the surface of the sphere will tend to give rise to magnetic force in the interior; but the magnetic force will only gradually pene.

trate into the interior, and electric curents circulating in the sphere in parallel planes will cause a magnetic force opposed to that due to the moving charges. If the conductivity be perfect, these currents will persist, and the interior of the sphere will be permanently free from either electric or magnetic force; but, with finite conductivity, the currents will die away, and the magnetic force will finally attain a definite value inside the sphere, although the electric force vanishes. In each of these cases a solution is easily found; but while the currents are dying away the magnetic energy gradually changes, and the calculation of the energy at any given time might be difficult. I therefore confine myself to the two limiting cases. The case of the final stage when there is finite conductivity I had solved when Dr. Heaviside suggested to me that I should include the case of infinite conductivity in my investigation. The present communication is the outcome of that suggestion.

The sphere is of radius a, and carries a charge Q at a speed u, which is very small compared with v, the velocity of light; the strength of the field is F, and the specific inductive capacity is c. I employ Dr. Heaviside's units in order that my results may be comparable with his. The origin is at the centre of the sphere, and the axes of x and y are respectively parallel to the direction of motion and to the direction of the uniform electric field.

When u/v is very small, the electric force E, due to the moving sphere, is the same as if the sphere were at rest, and is therefore derivable from a potential function. Since there is no electric force inside the sphere, the induced distribution on the sphere produces the potential Fy at internal points, and hence produces the potential Fay at external points. Thus at internal points the components of E are

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where, if we use C.G.S. electromagnetic units, we have μ=1 and c=(3x101o)-".

Infinite Conductivity. In this case a system of currents flows round the sphere, on its surface, in planes normal to the axis of 2, the distribution being such as to give rise to a magnetic potential -ucFz at internal points. The magnetic force due to these conduction currents then neutralises, at internal points, the magnetic force -ucF due to the moving charges. The external magnetic force due to the conduction currents will satisfy Laplace's equation for very slow speeds, and must, therefore, be expressible in zonal harmonics, while, for all speeds, the magnetic force normal to the sphere must be continuous. If z/r=cos v. the normal force at points just inside the sphere is ucF cos. The conditions are satisfied by the external potential

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If an electron be a conducting sphere of radius 10-13 cm. with a charge of 10-20 electromagnetic units, an electric force of a billion volts, or 1020 C.G.S. units, per centimetre, would not change its magnetic inertia by so much as one part in ten billions, and the results are of no consequence in experiments on the electrostatic deflection of kathode rays; but it is possible that there are other cases where it would be necessary to take the change of magnetic inertia into account.

When u becomes comparable with v, the analysis becomes more complicated, but does not present any difficulty, at least in the final stage, with finite conductivity, provided a Heaviside ellipsoid be substituted for a sphere.

In conclusion, I desire to acknowledge the help I have received from Dr. Heaviside's suggestions, and to thank Mr. Norman R. Campbell for verifying the formulæ. G. F. C. SEARLE.

The Date of Easter.

THAT the formula of Gauss for finding the date of Easter fails in certain cases, of which the year 1954 is one, was pointed out by Gauss in his original paper in the Monatliche Correspondenz (vol. ii., p. 129), where he shows that there are the following two exceptions to the formula in the Gregorian calendar :

(1) When the formula gives April 26, Easter falls on April 19.

(2) When the formula gives d=28, e=6, while 11M+11 divided by 30 gives a remainder smaller than 19, then

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