250 



SCIENCE 



[N. S. Vol. XXVI. No. 660 



in mustard (Science, Vol. 19, page 583). 

 Of the eighty samples examined only six 

 contained boric acid to exceed 1 part in 

 100,000. Five of these samples were ex- 

 amined for boric acid by Thompson's 

 method, with the following results: 0.020 

 per cent., 0.096 per cent., 0.202 per cent., 

 0.064 per cent., 0.080 per cent. All of the 

 samples which ran high in boric acid were 

 obtained from the western part of the 

 United States, and the majority from 

 Nevada. 

 Soluhilities of Food Colors: Edward Gude- 



MAN, Suite 903-4, Postal Telegraph 



Building, Chicago. 



Preliminary report on collaboration work 

 with Professor E. R. Ladd, Associate 

 Referee on Colors, Association Agricultural 

 Official Chemists. 



The solubilities of three coal tar colors, 

 Oraline Yellow, Turquine Blue and Ama- 

 ranth Red, and of three vegetable colors, 

 Aecoline Yellow, Lazuline Blue and Clad- 

 onal Red, were determined in cold and hot 

 water, muriatic acid (1 per cent.), am- 

 monia (1 per cent.), ether, petroleum ether, 

 ethyl, methyl and amyl alcohols, acetone, 

 acetic and amylie ethers, carbon disulphide, 

 class; and conclusions drawn were that 

 solubilities of the colors themselves and of 

 the extraction values of the solvents are 

 no criterion to judge the character nor the 

 class of the colors, and that such methods 

 are of no value in differentiating between 

 coal-tar and vegetable colors. 

 BeterndnaUon of Bone Acid in Butter: 



Robert Harcourt. Reported by title. 

 Meat Extracts and Juices: W. D. Bigelow 



and F. C. Cook. Reported by title. 

 Notes upon Composition and Atialysis of 



100 Americam, Honeys: C. A. Browne, 



Jr. Reported by title. 



B. E. Curry, 

 Secretary 

 New Hampshire College 



SCIENTIFIC BOOKS 

 A Laboratory Manual of Invertebrate Zoology. 



By GiLMAN A. Drew, Ph.D., professor of 



biology at the University of Maine. Pp. 



vii + 201. Philadelphia and London : W. 



B. Saunders Company, 1907. $1.25 net. 



Por the majority of our students the value 

 of our biological courses lies not in the acqui- 

 sition of a more or less detailed knowledge of 

 a series of animals or plants. Such a knowl- 

 edge is, of course, a necessity in training the 

 specialist, but the average student soon forgets 

 the number of podobranehs and pleuro- 

 branchs of the lobster, never remembers long 

 the exact position of the synergides and in 

 sis months' time can not tell whether yellow or 

 green is the Mendelian dominant in peas. 

 The greatest gain to the student is in a train- 

 ing of the powers of observation and the cul- 

 tivation of a spirit of independence which does 

 not accept a thing as so upon the ipse dixit of 

 the text. 



From this standpoint Drew's laboratory 

 manual seems most excellent pedagogically. 

 It does not tell him what he will find (and 

 usually he will find it if so told), but it asks 

 him what he does find and refers him to the 

 specimens for the answers. In the hands of 

 the competent teacher the resulting training 

 is most excellent, while such directions in the 

 hands of an incompetent instructor — well, 

 such books will force the incompetent into 

 other lines. 



The proof of the pudding, says the old say- 

 ing, lies in chewing the string. Just so the 

 real test of this as of all other class books, 

 lies in its actual use with students. As far 

 as one may judge from reading the pages. Dr. 

 Drew has produced a work .of real value. 

 Twelve groups of invertebrates are recognized, 

 and in each, detailed directions for the study 

 of one or two forms are given and accompany- 

 ing these are hints for the external study of 

 allied forms. If these are followed out they 

 afford ample illustration of the tables of 

 classification with which each group is intro- 

 duced. More matter is introduced than can 

 be used in the ordinary year's course, but this 

 is not a disadvantage, as it allows a choice of 

 forms according to the exigencies of location. 



