FOODS AND CONDIMENTS 175 



give an incomplete emulsion and there always remains a sediment. 

 The older the preparation the more incomplete is the solution. We 

 here approach once more a phenomenon which was touched upon under 

 "Aging of Colloids" (p. 74). J. G. M. BULLOWA informs me that 

 JUST and HATMA KER have invented a process which avoids these 

 disadvantages and which is already in use on a large scale. 1 



Cream is a fat emulsion which contains at least 1Q per cent fat. 

 Cream for whipping contains as much as 30 per cent. This emulsion 

 has the property of building thick foam walls which possess con- 

 siderable consistency. In order to simulate a high fat content, 

 potato flour, gelatin or whipped white of egg are added as adulter- 

 ants to cream deficient in fat. Calcium saccharate may also raise 

 the viscosity. S. M. BABCOCK and H. L. RUSSEL* recommended its 

 addition to milk or cream which has become thin from being heated. 

 The food industry has adopted this and, nowadays, calcium sac- 

 charate solutions enter commerce under various names (grossin, etc.) 

 as thickeners. According to FR. ELSNER, their effect is quite mar- 

 velous. Their detection is easy by the method of ROTHENFUSSER, 

 described on page 174. An artificial cream may be obtained by 

 emulsifying warm margarine with skim-milk and adding egg yolk. 



It is evident from what was said on pages 15 and 34, why an 

 emulsion such as whipped cream or the like is so stiff, because we 

 know how great a force is necessary to deform spheres of such small 

 size. 



In milk and cream, the aqueous colloid solution is the dispersing 

 medium and the fat is the dispersed phase; in the case of butter this 

 relation is reversed. 2 According to law, butter may not contain 

 more than 16 per cent water, though it is possible to impregnate 

 it with water to more than 30 per cent." According to POSNJAK, 

 the addition of alkalis and glucose increases, whereas increase of 

 acidity diminishes the capacity of butter to absorb water. (W. 

 MEIJERINGH.*) The kneading in of water is always reckoned to 

 be an adulteration, because water is cheaper than butter. From 

 the standpoint of the colloid chemist, it has always been a question 

 whether the amount of water in butter or rather the content of skim- 

 milk does not increase its digestibility and whether it is not the 

 dispersion by means of the albumin or rather casein-containing 

 aqueous solution which makes butter so much superior in digesti- 

 bility to other fats of high melting point; and whether, if the above 

 assumption should be proved correct, it would not be possible to 

 find a legal way to permit butter to have a greater water (i.e., skim- 

 milk) content. In the manufacture of margarine, skim-milk is 



1 [MERRALL and SOULE of Rochester, N. Y., spray milk into heated air to 

 dry it. Tr.] 



2 [See work cf MARTIN H. FISCHER and G. F. L. CLOWES. Tr.] 



