86 



BUJARD AND BAIER METHOD. a 



The finely divided material is extracted repeatedly with 80 per cent alcohol, and 

 the extract diluted with twice the quantity of water. Allow to stand until cold and 

 filter, several times if necessary, until filtrate is clear. Place on the white surface 

 and observe whether the solution is colored; if this be the case, evaporate on water 

 bath to about 20 cc; allow to cool and filter. Examine the filtrate for coal-tar colors 

 by methods given under wines. 



KLINGER AND BUJARD METHOD,* MODIFIED BY BREMER.c 



Twenty grams of finely minced material are heated for several hours with two vol- 

 umes of a mixture of equal parts of glycerin and water made faintly acid with tartaric 

 acid. The yellow solution freed from fat is filtered and the carmine precipitated 

 with alum and ammonia as a lake. On placing the test tube before the microscope, 

 the absorption lines of carmine-lake, lying between B and D, may then be identified. 

 Since the acid solution of the sausage-coloring matter is yellow, while carmine-lake 

 gives a red solution with acids, the carmine may be present in the sausages in some 

 form combined with the preservatives insoluble in alcohol. Weller and Riegel con- 

 cluded that this method was only reliable when the coloring matter could be precip- 

 itated from its solution as a lake. Since many vegetable colors, which are soluble in 

 water but insoluble in alcohol or amyl alcohol can not be precipitated as lakes, this 

 method may often fail. 



SPAETH METHOD d 



Heat the finely divided material for some hours on the water bath at 100 C. and 

 then extract with ether. The fat-free substance is then warmed on the water bath 

 with a 5 per cent solution of sodium salicylate for one hour. The solution is filtered 

 and ammonia added to one portion; observe whether a lake separates. As ammonia 

 may sometimes give red precipitates, consisting of calcium and magnesium phosphates 

 and possibly aluminum hydroxid carrying down traces of anilin colors mechanically, 

 the precipitate obtained, if any, must be further examined for carmine. Another 

 portion of the filtrate is acidified with sulphuric acid and heated with wool free from 

 fat and examined for coal-tar colors, as under wines. It is not necessary to remove 

 the precipitated salicylic acid before dyeing the wool. 



MICROSCOPIC EXAMINATION (MARPMANN).* 



A section of the sausage or other meat, about 1 cm thick, is thoroughly moistened 

 with 50 per cent alcohol and examined under the microscope. When only 

 traces of coloring matter are present, the substance is dehydrated in xylol, which is 

 expelled by means of carbon tetrachlorid, and the mass placed in cedar oil. As 

 thus prepared it is transparent and coloring matters can readily be recognized. 

 Fuchsin, magenta red, diamond red, carmine, logwood, and archil stain the cell sub- 

 stances, while acid anilin colors dye the liquid in the cell. In some instances (e. g., 

 with safranin) the coloring matter must be concentrated and wool or animal tissue 

 placed in the concentrated solution. The finely-divided substance is digested with 



oHilfsbuch fur Nahrungsmittelchemiker, 1900, p. 163. 



& Zts. angew. Chem., 1891, p. 515. 



c Forschungsberichte, 1897, p. 45, 216; C. A. Mitchell, Flesh Foods, p. 143. 



<*Pharm. Centralb., 1897, 38, 884; Zts. Nahr. Genussm., 1901, 1020. 



Zts. angew. Mikros., 1895, p. 12; C. A. Mitchell, Flesh Foods, p. 142. 



