March 12, 1908] 



NA rURE 



437 



deal satisfactorily with the pathclcgical side, and it is 

 a question whether such morbid processes as those of 

 tumours would not be better omitted. In any case, 

 we cannot ajjree with such statements as : — " True 

 cancers are not common to animals," and, further, that 

 cancers " are most frequent on the head and lower 

 part of the leg's." In the section on tuberculosis, the 

 author is satisfied to leave the question of the identity 

 or otherwise of human and bovine tubercle with 

 Koch's original statement of non-communicability, 

 ignoring all that has been done on the subject since 

 that statement was made. S^he other conditions, 

 for example, rickets, are very inadequately described. 



So far as this country is concerned, there is still 

 room for a good up-to-date popular scientific work 

 which will give the farmer such simple knowledge of 

 the breeding, accidents, and diseases of his animals 

 as will show him the occasion and the wisdom of 

 consulting the skilled veterinarian. G. L. 



I'raile de Cliiniie analytique qualilutivc. siiivi dc 

 Tables systemaliqtics pour I'Aiialyie mineralc. By 

 Louis Duparc and .Alfred .Monnier. Second edition. 

 Pp. viii 4-374. (Paris: Felix .Mean; Geneva: 

 l.ibrairie Kiindig, K)o8.) 



The iirst edition of this book on analytical chemistry 

 appeared in iqoo. In the present, second, edition 

 there has been added a preliminary theoretical portion 

 with the object of giving an insight into the reactions 

 which take place during the analytical operations ; 

 this new portion gives an account of the atomic 

 theory, the theory of solutions, and the theory of 

 chemical equilibrium. Then follows the usual de- 

 scription of apparatus, reagents, and methods of 

 manipulation. The main portion of the book is occu- 

 pied bv an enumeration of the reactions of the bases 

 and acids, including the more common organic acids, 

 ;md more brieflv of the rare metals and alkaloids. 

 In each case the reactions which take place are ex- 

 pressed bv chemical equations. The book is intended 

 to be a laboratory companion and work of reference 

 not onlv for the student but also for the analytical 

 chemist. Its value, however, for reference purposes 

 is much lessened bv the want of an index, though a 

 full table of contents is given at the end of the 

 volume. 



Actiialiles scientifiques. By .Max de Nansout}'. Pp. 



316. (Paris: Schleicher Freres, 1907.) Price 3.50 



francs. 

 Tins volume is the fourth issue of an interesting and 

 useful annual publication which on previous occasions 

 we have commended to the notice of science students. 

 Now that abilitv to read French is expected of science 

 graduates in the University of London, books which 

 provide means for a student to enlarge his vocabulary 

 and at the same time to improve his knowledge of 

 science should be very popular. The selection of 

 subjects is very wide ; e.g. articles are included on 

 colour photography, the extraction of gold from the 

 sea, spontaneous combustion, laughing, and artificial 

 flowers. 



(i) California aud lb,- Caliloniiaiis. Pp. 48. (2) 



The .Ups <./ Kiiig-Kerii Divide. Pp. 22. By 



President D. S. Jordan, Stanford University. (San 



Francisco : .\. M. Robertson, 1907.) 



TilKSE are two readable essays, the first of which 



appeared in the .itlantic Monthly ten years ago, while 



the other is reprinted from " Out \A'est." The 



booklets should be read by visitors to California, and 



they may be commended also to the general reader, to 



wh( ni the excellent illustrations will be an interesting 



feature. 



NO. 2002, VOL. 77] 



LETTERS TO THE EDITOR. 



\The Editor docs not hold himself responsible for opinions 

 expressed by his correspondents. Neither can he ttndertake 

 to return, or to correspond with the writers of, rejected 

 matniscripts intended for this or any other part 0/ Nature. 

 No notice is taken oj anonymous communications.] 

 The Isotnerm,.! Layer of the Atmosphere. 

 TuosE who, like myself, have followed with interest, but 

 at a distance, the attempts made during recent years to 

 obtain direct information as to the meteorological condi- 

 tions of the upper atmosphere, cannot but have felt a 

 curiosity on some points which Mr. Dines's letter in 

 Nature of February 27 serves to deepen. To one who has 

 had experience of the vagaries of self-recording- instru- 

 ments, the first question that suggests itself is what 

 degree of reliance can be placed on the results obtained 

 during individual ascents, whether of kites or of balloons. 

 Supposing a temperature of —70° F. recorded, the total 

 range of temperature between the ground and the " iso- 

 thermal layer " will usually have exceeded 100° F. ; thus 

 a 3 per cent, or 4 per cent, error in the scale — an amount 

 not infrequently exceeded in ordinary thermographs limited 

 to ordinary surface temperatures — would sufifice to give an 

 uncertainty of 3° F. or 4° F., which seems all that Mr. 

 Dines is prepared to allow. But, apart from mere scale 

 errors, is it certain that there are no other sources of 

 uncertainty in meteorograph records from kites or balloons 

 even when these are sent up after nightfall? 



Before attempting to explain such large differences as 

 Mr. Dines mentions between the temperatures in the 

 " isothermal layer," shown by meteorographs sent up on 

 the same day from stations only a few hundred miles 

 apart, one would like to know exactly what the evidence 

 is that the temperatures recorded differ at most only 3° F. 

 or 4° F. from the true ones. The following questions 

 naturally suggest themselves : — 



(i) Are the instruments tested over the whole range 

 encountered in the atmosphere, both before and after an 

 ascent? 



(2) Has it been a frequent practice to send up two or 

 more thermographs with the same balloon, or witli separate 

 balloons, but at the same station and at the same time, and 

 if so, have they always given closely accordant results? 



(3) Has it been established by actual trial that the 

 different types of meteorographs, English and foreign, when 

 sent up at the same time from the same station, give a 

 satisfactory agreement? 



Mr. Dines mentions a case when the temperatures found 

 for the " isothermal layer " at three English stations on 

 the same day varied from —42° F. to —74° F. An un- 

 certainty of +4° F. could account for only a quarter of 

 this, but an uncertainty of +8° F. might account for a 

 half, and an uncertainty of + 16° F. for the whole. Now 

 is there conclusive evidence that uncertainties of the order 

 + 10° F. are quite out of the question? 



March 3. Charles Chree. 



The Solidification of Helium. 



In the telegram from Prof. Kamerlingh Onnes 

 announcing the solidification of helium, the statement is 

 made that " the last evaporating parts show considerable 

 vapour pressures as if liquid state is jumped over " — in 

 other words, it apparently sublimes. 



I have for a long time expected that this would be the 

 case. When the boiling points and melting points of the 

 non-valent elements are plotted against their atomic 

 weights the curves nearly meet, the two points for argon 

 being very near to one another. By a slight extrapolation 

 they may be made to meet, and they then do so for an 

 atomic weight much higher than that of helium. Now if 

 an element corresponded to the meeting point its triple 

 point would be given by the temperature at the join. 

 Elements of lower atomic weight would sublime instead 

 of melting. This Is apparently the case for helium, and 

 it is a moot point whether or not it will be found to be 

 also so for neon. The uncertaint}' arises from the rapid 

 drop in the curves in passing to the row of elements N, O. 

 Fl, to which neon belongs.* Each curve can be represented 

 very nearly by a parabola. .\i.fred \V. Porter. 



University College, I^ondon, March 6. 



