210 EXPERIMENT STATION EECORD. 



cyclic nitrogen compounds do not give tlie slightest color. In a few cases some 

 violet color was developed, but in the check experiments without the formic 

 aldehyde the same color exactly was &hown; this was never the case with the 

 proteids tested, and this fact enables us to distinguish the proteids from the 

 nonproteids, so far as tested. In other words, the formic aldehyde -reaction, as 

 fas as tested, is much better than the biuret reaction, for it enables us to differ- 

 entiate complex ijroteids from sut^h compounds as polypeptids. uric acid deriva- 

 tives and pyrimidins." 



The author intends to continue his investigation, ))ut " it can be stated now 

 that a concentrated solution of formic aldehyde must not be used, and that one 

 of the concentration 1 : 5UUU is very satisfactory." Other aldehydes, ketones, etc., 

 will be tested. 



Rapid method for determining glucose with Fehling's solution, G. Lafon 

 (Compt. Rend, /b'oc Biol. [Paris], 62 (lOOH), No. 18, p/>. 9JiS-DoO).—A moditica- 

 tion of Bernard's method is described, which, according to the author, tits it for 

 general use. 



The value of different color reactions for identifying pentoses, F. Sachs 

 (Blochcm. Ztschr., 1 (1906), No. 5-6, pp. 383-398). — From a comparison of meth- 

 ods for clinical purposes the author concludes that though it has limitations the 

 Neumann reaction is very satisfactorj' for diagnosing pentoses and preferable 

 to the original orcin method or this method as modified by Bial. 



Practical methods of detecting boric acid, J. Peeschek {Die praktisrhin 

 Methodcii dcr Bestimmmuj und des Navhiceises dcr Borsdure. Liibeclc: Charles 

 Coleman, pp. 56, figs. 6). — A summary and discussion of the detection of boric 

 acid in the examination of feeding stuffs under the provisions of the German 

 meat inspection law of June, 19CX). 



Examination and valuation of raspberry jam, E. Baier and P. Neumann 

 {Ztschr. Jnterstich. Nahr. ii. Geniissmtl., 13 {1907), No. 11, pp. 67.7-680).— Rasp- 

 berry jam contains on an average more material insoluble in water than similar 

 goods from other fruits, the values in jams examined- ranging from 4.2 to 9 per 

 cent. In the author's opinion, the ratio between water soluble material and 

 bugar-free extract insoluble in water and between the alkalinity and the 

 material insoluble in water are factors of decided value in judging of purity. 

 A microscopical examination is also important. 



Examination and valuation of ground black pepper, F. Haktel {Ztschr. 

 Untersiich. Nahr. ii. Gciitissmtl., 13 {1907), No. 11, pp. 665-675).— The analytical 

 data rei)orted are discussed on the basis of judging the quality of pepper. When 

 the crude tiber content is about IT per cent the author believes that determina- 

 tions of the glycogen value are desirable, as this factor is not so affected by dry- 

 ing. In general, the determination of both these values is to be recommended. 

 The author regards G.5 per cent as the maximum value for ash content. Ap- 

 pended to the article are a number of formulas for mixing pepper. 



A new method for the determination of nicotine in tobacco, W. W. Garner 

 {V. S. Dept. Agr., Bur. Plant Indus. Bui. 102, pp. 61-69). — Six gm. of the pulver- 

 ized air-dried material is treated with 3 to 5 cc. of a 5 per cent solution of sodium 

 hydroxid and extracted for about 4 hours with 100 cc. of gasoline. Traces of 

 ammonia are removed from To cc. of the filtrate by allowing it to stand for 1 

 hour, after which 10 cc. of fifth-normal sulphuric acid in 50 cc. of water is added 

 and the mixture shaken in a separatory funnel. The aqueous laj^er is then 

 drawn off and the gasoline washed twice with water. The excess of sulphuric 

 acid is titrated with tenth-normal alkali, using cochineal as an indicator. One 

 cc. of fifth-normal sulphuric acid is equivalent to 0.0324 gm. nicotine. 



Apparatus for the supply of carbon dioxid in the determination of nitro- 

 gen in organic compounds by the absolute method, G. Younu and B. Cauu- 



