398 



SCIENCE. 



[Vol. I., No. 14. 



that line of investigation. About two years 

 ago, Prof. G. F. Becker published his ''Di- 

 gest ' ; a j-ear later my own ' Recalculation ' 

 appeared ; and now comes a third volume on 

 the subject by Professor Lothar Mej'er and 

 Dr. Karl Seubert of Tubingen. 



A comparison of this new work with the 

 other two shows, that, in general terms, it is 

 intermediate between them in its character. 

 Becker collected the data relative to atomic 

 weights, and brought them into systematic 

 shape, but attempted no thorough recalcula- 

 tion. Mej'er and Seubert classify and recal- 

 culate the published weighings, and make 

 many valuable reductions of apparent weights 

 to absolute or vacuum standards ; but, with a 

 few exceptions, they do not attempt to combine 

 the work of dilFerent investigators, and thej' 

 reject the method of least squares as inapplica- 

 ble to the data at hand. My own effort was 

 to reduce determinations as far as possible to 

 common standards, to combine all similar data 

 into general means, and to compute from all 

 the evidence the most probable values for the 

 atomic weights of the diff'erent elements. In 

 so doing, I applied the method of least squares, 

 and I see as j-et no reason for discrediting 

 that manner of discussion. Each of the three 

 volumes fills a definite place ; and, in any future 

 revision of the field, each will be found a use- 

 ful supplement to the others. 



In general, the results obtained by INIeyer 

 and Seubert difl"er but slightly from mine. In 

 comparing the atomic weights of sixty-six ele- 

 ments, the diflference between the two recalcu- 

 lations falls within a tenth of a unit in thirty- 

 seven cases, and is greater than a tenth in 

 twenty-nine ; but among the latter are found 

 most of the rarer and less perfectly known 

 metals. In manj' instances the differences 

 are due to a trifling fundamental difference in 

 the value assigned to oxygen. The Meyer- 

 SeubertvalueisO= 15.96 ; mineisO=15.9633 : 

 and this slight variation in the third and fourth 

 decimal places sometimes is multiplied among 

 the higher atomic weights to an appreciable 

 amount. Where the two recalculations agree, 

 they serve to confirm each other : where thej- 

 differ, they indicate the important fields for 

 further investigation. Most of the differences, 

 however, are mainlj^ due to differences in the 

 manner of computation. 



In some respects the new recalculation is 

 open to criticism. Inasmuch as Meyer and 

 Seubert rarel^' attempt to combine the available 

 data, they are, perforce, compelled, in dealing 

 with each element, to select more or less arbi- 

 trarily- the results of one investigation, and give 



it preference over all the others. This they do 

 without assigning reasons for their choice ; 

 and such a lack of critical statement is much to 

 be regretted. Again: the arrangement of the 

 material is inconvenient, notwithstanding the- 

 fact that there is a well-classified index, both 

 for elements and for authors. For example : 

 aluminum, instead of being discussed in a 

 division hj itself, is treated in separate ratios 

 on pp. 22, 23, 83, 139, 151, and 193; and 

 a comparison of the results of different in- 

 vestigations is thus rendered a ver^' trouble- 

 some matter. 



Some omissions are noteworthj', and seem 

 difficult to explain. Such, for example, are 

 Cleve's determination of the atomic weight of 

 scandium, Julius Thomsen's synthesis of water, 

 and Russell's hydrogen series for cobalt and 

 nickel. Russell's work on the oxides of these 

 metals is given, and his results receive final 

 acceptance ; but wherein they are preferable 

 to those of Lee is not stated. Another curious 

 set of omissions occurs under antimonj'. Here 

 are cited Professor Cooke's latest bromide 

 series, and his set of results comparing the 

 trisulphide with the chloride. But his synthe- 

 ses of sulphide from the metal, and his valu- 

 able iodide series, are altogether ignored, while 

 his earlier bromide series barelj- receives men- 

 tion. Finallj-, nothing is said concerning 

 Dumas' investigations upon the occlusion of 

 oxygen bj^ silver, although no recalculation 

 of the atomic weights can safelj' ignore so im- 

 portant a factor. F. W. Clarke. 



WILDER AND GAGE'S INTRODUCTION 

 TO ANATOMY. 



Anatomical technology as applied to the domestic cat: 

 an introduction to human, veterinary, and compara- 

 tive anatomy. ByBuHTG. Wilder, B.S., M.D., 

 and Simon H. Gage, B.S. New York and 

 Chicago, A. S. Barnes ^ Co., 1882. 25 + 575 p. 

 1. 8°. 



This book the authors state to have grown 

 out of their needs as instructors of students 

 preparing for practical work in human, veteri- 

 naiy, or comparative anatomy. To students 

 of the first and second of the above classes 

 there is no doubt it will prove extremely' use- 

 ful. It is probably correct to saj', that, al- 

 though containing a good deal of irrelevant 

 matter, and blemished by the unnecessarily 

 extensive employment of a novel terminology, 

 it contains hy far the best set of directions 

 for the dissection of a mammal below man in 

 the scale, ever published for the use of that 

 large class who prefer or are compelled to enter 



