444 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



orating the petroleum completely, dissolving 15 grains of the 

 residue in seven cubic centimeters of petroleum-spirit in a 

 well-closed flask, and placing the solution in water at 50 to 

 60 Fahr. for some hours. Fats of low melting-point being 

 more soluble than those of higher melting-point, the butter 

 fat remains in solution, while suet, tallow, and even lard, are 

 deposited, if present to the extent of more than 10 per cent. 

 21 A, October, 1873, 1064. 



EFFECT OF SALTING BUTTER. 



The well-known fact that in the whole of Northern Europe 

 all butter, without exception, is salted immediately on its 

 production, while in the Southern countries none but the 

 most inferior butter is either sold or used salted, led to the 

 investigation of the effect of the salt by Martini. This in- 

 cluded analyses of salted and unsalted butter by Professor 

 Miiller, and the conclusion was reached that the use of salt 

 is advantageous to both the consumer and producer. The 

 weight of the butter does not seem to be increased by the 

 salt, since the weight of the liquid worked out about equals 

 that of the salt added. The butter so treated is also found 

 to be but little, if any, richer in fat, but to keep better and 

 longer, not only on account of the antiseptic property of the 

 salt, but because it is also partially freed from caseine and 

 milk-sugar, the two ingredients which, in the presence of wa- 

 ter, impart the tendency to decomposition. The salt also 

 renders the working of the butter easier, apparently by par- 

 tially reducing the adhesion between the caseine and milk- 

 sugar and fatty particles, thus facilitating the removal of the 

 former, just as salt added to pure milk will cause it to filter 

 more rapidly, while caseine and milk-sugar pass into the fil- 

 trate, some caseine remaining with the fat on the filter. The 

 preference for unsalted butter in some countries Martini at- 

 tributes entirely to unfounded prejudice. 13 C, November 1, 

 1873,1373. 



IMPROVED MODE OF CONDENSING MILK. 



A simple and cheap method of condensing milk, devised by 

 Gfal, of Innsbruck, consists in heating the milk in a boiler to 

 from 150 to 160, and then pumping it up through pipes, at 

 the mouth of each of which is a perforated rose, like that of 



