FOODS HUMAN NUTRITION. 1155 



Report of State inspector of apiaries, M. E. Darby (Missouri Bd. Agr. Mo. 

 Bill.. 6 UHOS). yo. U, lip. 3-13, fi(j.s. 6). — During tlie season of 1908, 340 api- 

 aries and 5,155 colonies were lnsi)ected, of which IGO apiaries and 409 colonies 

 were found diseased. A brief account is given of foul brood and other bee 

 diseases. 



The hive and honey bee, L. L. Langstroth, rev. by C. Dadant (Hamilfoii, 

 111., I!W8, pp. T+J7'J. pis. 28. figs. 229). — A second revision of this work. 



A guide to the culture of mulberry trees and to the commercial raising of 

 silkworms, J. Bolle {Aiilcitinig ziir Kultur des Maulhrcrlxiiuiics mid zur 

 RationcIIcn Aiifzitcht dcr Scidctiraupv. Gorz, 190S, pp. T7/+/07. pis. 2, figs. 

 112). — In part 1 the author considers the culture of mulberry trees, their ene- 

 mies, diseases, etc. In part 2 a detailed account is given of the methods of 

 rearing silkworms, nature and treatment of the diseases affecting them, etc. 



Inheritance in silkworms, I, Y. L. Kellogg (Lei and Stanford Jr. Univ. 

 Pubs.. Univ. 8er., 1908, No. 1, pp. 89, pis. ^, figs. 2).— This is said to be a first 

 contribution of data and results derived from a general study of silkworm 

 inheritance. 



FOODS— HUMAN NUTRITION. 



On the presence of tin in certain canned foods {Local Govt. Bd. [Gt. Brit.], 

 Med. Dcpt., Rpts. Insp. Foods, 1908, \o. 7, pp. 30). — This document consists of 

 two parts, namely, a report of investigations and a discussion. 



General observations on the iiiqiiir!/, by G. S. Buchanan (pp. 1—4). — The 

 investigations reported in the following paper are briefly summarized and dis- 

 cussed. 



On the presence of tin in certain canned foods, together with some investiga- 

 tions on the to.vicologii of tin, by S. B. Schryver (pp. 5-30). — The author re- 

 ports the examination for tin of a large number of samples of canned goods, in 

 many cases five to seven years old. A colorimetric and gravimetric method 

 were used for the estimation of tin, the former depending upon the purple color 

 reaction obtained by the use of dinitro-diphenylamine-sulphoxid with stannous 

 chlorid in the presence of an excess of hydrochloric acid. I'nder the experi- 

 mental conditions described 0.25 grain of tin per pound of sample gave a marked 

 color. 



The procedure in the gravimetric method employed was for the most part 

 similar to that used for the colorimetric estimation. " The organic matter 

 was destroyed by a mixture of potassium sulphate and sulphuric acid, and the 

 tin prerii)itated from the diluted solution as sulphid. This was converted into 

 oxid, which was weighed as such instead of being estimated colorimetrically." 



As regards the results obtained, "the meat foods, as a class, appeared to 

 have taken up into their substance a comparatively small jiroportion of tin, 

 even after six years or more. Often the quantity of tin present in these meats 

 has been less than 0.5 gr. per pound; in only one instance (canned tripe) did it 

 reach 2 gr. per pound. Meat extracts of similar age, however, had absorbed 

 a considerably greater projiortion of tin, and the same in a less degree was the 

 case with meat essences. 



" Only one of the three samples of canned souj) of <> to S years old contained 

 tin in large quantities; in this instance the soui» no doul)t contained fruit acid 

 derived from tomatoes, (^anned lobstcn* of (5 to S years of age had absorlted as 

 nuich as 2..39 gr. r)f tin to the pound. . . . 



"The two samples of canned vegetables (parsnips and carrots, 6 to 8 years) 

 showed 1.5 and 2.19 gr. of tin per pound respectively. Canned jams and pud- 

 dings containing fruit, of the same age, took up considerably more tin than the 



