AGETCULTURAL CHEMISTRY. 4l9 



jtrt'seiit free ncid in honey be designated uialic acid, and that the acidity be 

 expressed in cnliic centimeters of normal allvali solntion per 100 gm. honey. 



Methods for the analysis of maple products and the detection of adul- 

 terants, together with the interpretation of the results obtained, A. II. Bryan 

 (U. S. Dci)t. Ayr., Bur. Chcm. Circ. 'lO, pp. 13). — This compilation of methods of 

 analysis of maiile products has I)een prepared for tlie convenience of food 

 analysts. The use and interpretation of analytical results in the detection of 

 adulteration are discussed. 



Amount of soluble silicic acid in cocoa beans, H. Matthes and O. Rohdicii 

 iZtschr. Offcntl. Chem., I4 {1!)08), No. 9, pp. 166-169). — In the determinations 

 reported the silicic acid content of different sorts of cocoa was found to vary 

 considerably and the authors do not believe that quality can be judged by this 

 constituent. 



Plant fats and fat mixtures used in chocolate manufacture in the place of 

 cocoa butter, O. Sachs {Chcm. Err. Fctt 11. Ilarz Indus., 15 (1908), Nos. 1. pp. 

 9, 10; 2 pp. 30-ii3). — The physical constants and other characteristics of differ- 

 ent fats used in place of cocoa butter in chocolate manufacture are described and 

 other data summarized with a view to the detection of such substitution. 



Comparative tests of different methods of measuring fat in milk, E. 

 Dehaye (Indus. Lait. [Parish, 33 (1908), Xo. 2.2, pp. J, 2 5-.'i 31). —In the studies 

 reported the author obtained larger results from chemical methods, such as the 

 Adams method of fat extraction, than from the mechanical-chemical methods, 

 such as the Gerber acid or salt method. In the case of fresh milk, or slightly 

 acid homogenized milk, or milk partly skimmed, the results by the Adams 

 method were slightly smaller than those l»y the Rose-Uottlieb method. In the 

 author's opinion the latter method is to be preferred for exact determinations. 



A milk constant as a basis of judgment, G. Cornalba (Indus. Lait. [Paris], 

 33 (1908), No. 26, pp. Ji95-'i99).— In the data presented the soluble matter in 

 milk has a fairly constant value, ranging from a minimum of 5.04 to a maxi- 

 mum of 6.44 per cent, while the insoluble matter in the same samples ranged 

 from 5.05 to 8.58 per cent. In the author's opinion such a constant value offers 

 tlie surest and most precise means of judging of the purity of milk, especially 

 with respect to the addition of water. 



Study of recent methods of analysis of butter, M. F. Jean (Indus. Lait. 

 [Paris], 33 (1908), No. 22, pp. Ji31-.'i3.'i). — Some methods recently proposed for 

 detecting adulteration of butter were tested by use of pure butter alone and 

 mixed with animal and vegetable fats. Sevei'al revealed adulteration when the 

 latter equaled 10 per cent, but they failed to give positive evidence when it was 

 not over 5 per cent. The method of Robin (E. S. R.. 18, p. 709) is mentioned 

 as of considerable value. 



Regarding' the nonsaponifying constituents of cocoa butter and their 

 detection in mixture with butter, II. INIattiies and E. Ackermann (Bcr. Dent. 

 Chcm. Gesell., J,l (1908), No. 10, pp. 2000, 2fl0/).— This is a preliminary notice 

 of investigations on a method of detecting the presence of cocoa fat in butter, 

 depending on the facts stated by the authors that cocoa butter contains a phyto- 

 sterin which gives customary color reactions but combines with 2 molecules of 

 l»romid and forms an acetattetrabroniid, whereas butter does not form the latter 

 oomi)onnd. According to the method described, 1 kg. of cocoa butter upon 

 repeated sai)onification and solution in ether yields 1.25 gm. of crude phytosterin 

 with a melting point of 135 to 140° and 0.25 gm. of volatile constituents. The 

 acetilized crude phytosterin (melting point 126 to 128°) is bromidized in ether 

 and glacial acetic acid. Upon standing, thin plates with a melting point of 180 

 to 183° separate. From the filtrate after evaporation and recrystallization of 



