I. AGRICULTURE AND RURAL ECONOMY. 399 



a paddle until it appears dry externally. For use in the 

 house it may be advisable to color the grain by adding one 

 five-hundredth part of liquid fuchsin. Clean the kettle after 

 use by scouring with lime. In most cities, however, the ar- 

 senite of potash can be obtained ready made, and thus the 

 trouble and danger of preparation is saved. 15 C\ 1873, 204. 



EFFECT OF TEMPERATURE ON THE CREAMING OF MILK. 



The results of a series of experiments, carried on through 

 several months, by exposing different 'portions of milk in pans 

 to temperatures of 40, 57, and 74, and determining the 

 amount of fatty matter still present after various times of ex- 

 posure, are embodied in a report by Schubert, from which it 

 appears that the separation of fatty matter from the milk was 

 most rapid at 40, but that it was more rapid at 74 than at 

 57, the separation being more complete at 40, in 18 hours, 

 than it was at 57, after 30 hours. After 24 hours at 40, 

 only 0.296 per cent, of the fatty matter remained in the milk; 

 and while diminution of it continued to from 30 to 36 hours, 

 it was so slight as to have no practical importance. Tests 

 made on a large scale of Schwartz's method of immersing the 

 milk in deep vessels in ice-water, showed that it produced 

 the largest yield of butter for equal measures of milk ; and 

 also that sweet cream afforded more butter than sour cream. 

 The method possesses the additional advantage that the milk 

 never sours, can be preserved several days in ice-water with- 

 out the least injury, and will bear transportation to a con- 

 siderable distance before becoming warm enough to change. 

 Cheese made from it is also much better, and less liable to 

 spoil in keeping ; and since butter made from sweet cream 

 contains less milk-sugar and caseine, according to the analyses 

 made, it is consequently less liable to become rancid. 28 C, 

 January, 1874, 65. 



PREPARATION OF CONDENSED MILK. 



The process of Professor Trommer is essentially as follows : 

 The milk from washed udders, after being strained and boiled 

 over a free fire, is again strained through a fine tin strainer 

 into shallow evaporating pans of heavy tin, and evaporated 

 on a water-bath, with continued stirring with a wooden paddle, 

 after the addition of from 3 to 3^ ounces of refined sugar for 



