AGRICULTURAL CHEMISTRY. 419 



not oalculatod from tlu> .•iiiKniiit ol' llir nitrom'ii it contiiins; (5) by centrifuging 

 tlio method is nMulcrcd nioro rapid tlinii by filtering, and the washing of tlie 

 lirecii)itate is more tliorongh : and (('<) drying of the precipitate is rapid. 



A simple method for the quantitative determination of proteids in milk, 

 T. R. B(k;(;s (/;///. Jiilnis lloiikhis Ilosp., 17 {tUnC). So. JS7. /ij). -i'li, .I'lA). — The 

 I)roteids in niillv diluted in the i)roiK)rtion of 1 : 10 are i)recii)itated in an Esbach 

 lube by means of a 10 per cent solution of phosphotungstic acid in about 3 per 

 cent hydrochloric acid. The rending of the i)recipitate is made after 24 hours. 



The rapid determination of water in butter, G. E. Patrick {Jour. Amer. 

 Vhcm. .S'oc, 28 (1906), No. II, pit. 1611-16J6).— The author expels the water 

 from 12 to 10 gm. of butter by boiling in a wide test tube over a naked flame. 

 The water content as indicated by the loss in weight by this method is be- 

 lieved to be seldom if ever more than ().."> per cent from the truth. 



Direct determination of water in butter and other fats, C. Aschmann and 

 J. r. Akkm) (Clicni. Ztfi., .in (190G), Ao. 7S, j). 9.5.J, fi;/. 1). — This is based upon 

 the distillation of the fat with xylol and the measuring of the water. 



The refraction of nonvolatile fatty acids of butter, W. Ludwig and H. 

 llAui'T (Ztsclir. I nivrsHch. Xalir. it. Gcini.s.snitl., 12 (WdG), No. 9, pp. 521- 

 523). — This is considered of value in determining the adulteration of butter 

 with 10 per cent or more of cocoanut oil. Butter from various sources showed 

 refractometer numbers of the nonvolatile fatty acids varying from 29 to 30.2 

 and palmin from 10.1 to 1G.5, while the addition of 5 per cent of palmin to but- 

 ter reduced the refractometer number of the nonvolatile fatty acids to 28, 

 the addition of 10 per cent to 2(>.9, the addition of 50 per cent to 22, and the 

 addition of 00 per cent to 17.1. 



On the detection of the adulteration of butter with cocoanut oil and oleo- 

 margarin, L. Robin {Compt. Rend. Acad. Sci. [Paris], IJ/S (1906), No. 15, pp. 

 512-51Ji). — The fatty acids in cocoanut oil are almost entirely soluble in 00 

 per cent alcohol at a temperature of 15° C, those of butter only partially soluble, 

 and those of margarin only slightly soluble. In water the fatty acids in but- 

 ter are much more soluble than those of cocoanut oil and margarin. 



These characteristics are believed to be sufficient to enable the determination 

 of mixtures of cocoanut oil and margarin with butter, and a method of pro- 

 cedure for this ])urpose is outlined. 



On the detection of formaldehyde in milk, S. F. Agree (Jour. Biol. Chem., 

 2 (190()). No. 1-2, pp. l'i5-l',S). — Act-ording to the author's investigations 

 Ilehner's test for formaldehyde in milk depends upon the presence of casein 

 .•ind lactalbumin. and the intensity of the color bears a relationship to the 

 amount of these substances present. Of several aldehydes tested (acetaldehyde, 

 paraldehyde, chloral hydrate, benzaldehyde, cuminol, and vanillin) vanillin 

 alone gave the same reaction as formaldehyde. Other complex proteids as 

 well as casein and lactalbumin gave the violet color with formaldehyde and 

 sulphuric acid. The glolmlin from squash seed was found to give the most 

 intense color and this substance was made use of in detecting formaldeliyde in 

 milk in concentrations less tlian -1 to 250.000. A method for this jmriiose is 

 suggested. 



Determination of salicylic acid in canned tomatoes, catsups, etc., W. L. 

 Diiiois (Jour. Anicr. Vhein. Hoc, 28 {1906), No. 11, pp. 1616-1619).— By the 

 uiethod suggested the color is removed before extraction with ether. The ma- 

 terial is rendered alkaline witli ammonia and then treated with milk of lime. 

 In the filtrate from this mixture the salicylic acid is determined colorimetric- 

 ally. 



Boric acid: Its detection and determination in large or small amounts, 

 W. II. Low {Jour. At)ier. Chnn. .s'oc, 2S {1906), No. 7. pp. 807-823, litis. 2). — 



