410 EXPERIMENT STATION RECORD. 



tion three times. Precipitate tlie clay in tlie solution by means of ammonium 

 chlorid. Collect tliis clay witli the iron and alumina precipitated from the 

 original hydrochloric acid solution on a filter, wash, ignite, and weigh. With 

 soils having a clay content of 1-15 per cent, divide the weight obtained by 0.99, 

 with those containing 15-30 per cent by 0.98, and with those containing 30-50 

 per cent by 0.97." 



The calculation of the potash content of potassic rocks from the specific 

 gravity, C. Przibylla (Kali, 1909, pp. 117, IIS; abs. in Chem. Ztg., 33 {1909), 

 No. 56, Rcpcrt., p. 259). — The method is not considered reliable. 



The estimation of iron oxid and alumina in phosphate rocks, T. S. Gladding 

 (Jour. Indus, and Engin. Chem., 1 (1909), No. Jf, pp. 2-'i9, 250; ahs. in Jour. 8oc. 

 Chem. Indus., 28 {1909), No. 9, p. 1/85). — The method proposed is as follows: 



" Boil 5 gm. of the rock phosphate for 1 hour in 50 cc. hydrochloric acid 

 (1:1), filter into a 250 cc. flask, add a few cubic centimeters of peroxid of 

 hydrogen solution, boil for a few minutes to oxidize iron and expel oxygen, cool, 

 fill to mark, and mix. Take 25 cc. {i gm.), heat to boiling, add ammonia to 

 alkalinity, then hydrochloric acid till just clear, then 1 gm. of oxalate of am- 

 monium in crystals, boil gently for a short time, let settle and filter from pre- 

 cipitated oxalate of lime into a 500 cc. Kjeldahl flask, add 5 cc. concentrated 

 sulphuric acid, evaporate to white fumes to destroy excess of oxalic acid. 

 (This boiling down and destruction of oxalic acid can be done in 20 minutes.) 

 Cool, add 50 cc. water, 5 cc. strong hydrochloric acid, and boil gently a few 

 moments to dissolve any dehydrated sulphate of iron, boiling until solution is 

 clear. Rinse into beaker, make up to about 150 cc. and precipitate the iron 

 and alumina as phosphates either by adding ammonia to neutrality using methyl 

 oi'ange as an indicator, or by making the solution just alkaline with ammonia, 

 just clearing with hydrochloric acid and then adding 25 cc. of acetate of am- 

 monia solution (sp. gr. 1.04). Filter and wash the precipitated phosphates with 

 a boiling hot nitrate of ammonia solution (2* per cent). Ignite and weigh, 

 deduct the iron phosphate present and multiply the remainder by 0.418 to obtain 

 the alumina. 



"The iron oxid is determined by taking 50 cc. (1 gm.) of the rock phosphate 

 solution and titrating by either bichromate of potash solution or permanganate 

 of potash solution." 



Determinations of the water-absorptive power of peat litter, A. G. Palm- 

 QUiST {K. Landthr. Akad. Handl. och Tidslcr., Jfl {1908), No. 5-6, pp. 398- 

 402). — This article gives briefly the results of a critical examination of various 

 methods which have been proposed for this purpose, particularly those of 

 Fleischer and von Feilitzen. Attention is called especially to the importance 

 of having the same bottom area in the apparatus used and of employing the 

 same quantity of peat. 



Hydrolysis of crystallized albumen from hen's egg, T. B. Osborne, D. B. 

 Jones and C. S. Leavenworth {Amcr. Jour. Physiol., 2-J {1909), No. 2, pp. 

 252-262). — Results of studies of the cleavage of crystallized egg albumen are 

 reported in comparison with the work of other investigators. Of the 50.08 per 

 cent of hydrolysis products obtained, the constituents present in greatest quan- 

 tity were leucin, glutaminic acid, and phenylalanin, with 10.71, 9.10, and 5.07 per 

 cent, respectively. 



" The low summation shown by our hydrolysis is not due to any defect in 

 carrying out the processes incident to the isolation of the amino-acids, for 

 throughout the entire analysis the separations were effected .with unusually 

 small losses. The unusual deflciency, in our opinion, is rather to be attributed 

 to the presence of some nonpi'otein complex which, in combination with protein. 



