191'J] AGRICULTURAL CHEMISTRY— AGROTECHNY. 411 



to make a concentration Of 5 per cent, phosphotungstlc acid was added to pre- 

 cipitate the antineiiiilic substance. The precipitate, washed With sulphuric acid 

 and with alcohol and dried in a desiccator over sulphuric acid, was used f<>r 

 nitrogen determinations by both the KJeldahl and Dumas methods. The differ- 

 ence in the values of the vitamin in the original samples, calculated from the 

 Kjeldahl and the I Mimas nitrogen, is considered to represent one-fourth of the 

 true vitamin content. 



The values for the vitamin content of Philippine vegetables determined by 

 this method are in general higher than the results found by Punk (B. 8. H.. 30, 

 p. 50S) for milk, but are considered to have comparative value. 



The formation of ammonia and amins in canned sardines during storage, 

 F. C. Wkbeb and J. B. Wilson (Jour, Indus, and Eni/in. ('Item., 11 (l'Jl'J). Xo. 2, 

 pp. 121-126). — This Is a report of investigations conducted during the seasons 

 of 1913 to 1916 of the sardine industry of Maine by the Bureau of Chemistry 

 of the U. S. Department of Agriculture. 



In following the degree of spoilage of the fish, ammonia determinations were 

 made by titration and by nesslerization of the volatile alkaline materials. 

 Variations in the results obtained by the two methods led to the conclusion that 

 the packed goods on standing undergo a change with the liberation of auilns. 

 A comparison of the amounts of ammonia and annus in old packs of sardines 

 and in various experimental packs showed that directly after processing the 

 volatile alkaline material contains practically two-thirds ammonia and one- 

 third alkyl amins. During storage at room temperature, the proportions appear 

 to change slowly, until alter a long period of standing the total alkaline mate- 

 rial contains about equal amounts of ammonia and amins. When stored at 

 a temperature just above freezing, the total quantity of volatile alkaline mate- 

 rial produced is much less than that produced when stored at ordinary tein- 

 peratures. This difference is considered to be an indication that these changes 

 may be caused in some instances by bacterial growth. The amins consisted 

 chiefly of triamin with small quantities of monainin and diamin. On prolonged 

 storage the monamin is apparently converted into diamin. 



The authors consider that it is doubtful whether the quantities of ammonia 

 and amins in the canned product have any direct relation to the keeping quali- 

 ties of sardines, although it has been shown that they have a decided bearing 

 upon the detinning of the interior of the cans. 



Microscopic color reaction for wheat, rye, and potato starch in the same 

 sample, E. Unna (Ztschr. Untersuch. Nahr. u. OenuasmtL, 86 (191S). Xo. 3-4, 

 pp. 49-53, pi. 1). — The solutions used for staining are as follows: (1) Water 

 blue-orcin mixture, consisting of 1 part water blue, 1 part orcin, 5 parts glacial 

 acetic acid, 20 parts glycerin, and 50 parts 86 per cent alcohol, made up with 

 water to 100 parts; (2) 1 per cent alcoholic solution of eosin ; (3) 1 per cent 

 safranin solution: (4) 0.5 per cent potassium bichromate solution. 



The flour, after preliminary treatment with 3 per cent phenol solution, is 

 washed and a small portion allowed to dry on a microscope slide. The slide is 

 then treated for 10 minutes with 1 gm. of the water blue-orcin mixture dissolved 

 in 6 drops of the eosin solution. After washing with water, the slide is placed 

 in the safranin solution for from 15 to 20 minutes, thoroughly washed again 

 with water, and placed for from 20 to 30 minutes in the potassium bichromate 

 solution. It is then washed with water and alcohol, dried, mounted, and 

 examined under the microscope. 



A plate is given showing the colors produced. Potato starch is colored red, 

 with a concentric blue ring; wheat starch pink, with the surrounding gluten 

 protein blue ; and rye starch a brownish yellow. 



