WAYS OF PRESERVING FOOD. 625 



count of the amount of sugar required to make it efficient. Dr. Berscb 

 has suggested a way of cheapening it by adding salicylic acid to the 

 sugar. His directions are to dissolve 100 grammes of sugar and 

 three grammes of salicylic acid in hot water, and to pour the solu- 

 tion, after it has cooled to about 100, over the fruit to be preserved. 

 If the fruits are wholly covered with the solutions they can be kept in 

 open vessels without changing ; but it is best to seal the vessels with 

 salicylic-acid paper (made by dipping common writing-paper into an 

 alcoholic solution of the acid), so as to keep out the dust. Thus pre- 

 pared, a ten per cent sugar-solution is strong enough for such fruits as 

 cherries, apples, pears, etc., and an eighteen to twenty per cent one 

 for the sweeter fruits. A difficulty in the application of this process 

 arising out of the qualities of salicylic acid as to solubility may be ob- 

 viated by previously dissolving the acid in glycerine. The old-fash- 

 ioned way of packing meat in salt and saltpeter is bad, because it 

 takes all the juices from the meats. It is preferable to prepare a brine 

 by heating a kilogramme of salt, 160 grammes of white sugar, and 80 

 grammes of saltpeter in six litres of water over a gentle fire, and pour 

 the mixture, after it has been cooled, over the meat. 



Fruits, cucumbers, and meat, may be preserved for a long time 

 with vinegar, by processes which are too well known to require a close 

 description. Meat is not generally preserved by the direct action of 

 vinegar, but by the vapors of acetic acid. For this purpose the meat 

 is placed on a shelf in a cask, in the bottom of which concentrated 

 vinegar has been poured. The escaping acetic vapors exercise a pre- 

 servative influence which is effective for a considerable time. The 

 processes of pickling and smoking are so well known that we speak 

 particularly only of a rapid-smoking process, which consists in painting 

 the meat some three or four times with a brush dipped in pyroligneous 

 acid, after which it acquires the taste and properties of well-smoked 

 meat. 



The processes of direct drying, which have long been employed 

 with fruits, have more recently been applied to vegetables. By late 

 improvements they have been brought to a degree of perfection in 

 which the freshness, taste, and tenderness of the fruits and greens, are 

 well preserved. Potatoes are dried by Casseten, at Lubec, into a light, 

 citron-yellow, gummy, transparent mass, which, when cooked with 

 water and a little salt, regains the color and mealy consistency of the 

 original tuber, and can not be distinguished by its taste from a freshly- 

 cooked potato. 



Meat is dried, by the processes of Endemann and others, into a 

 very nourishing food. By Endemann's method, the meat, cut into 

 slices, is placed in a chamber heated to a temperature of about 140, 

 in which a current of air of the same temperature is kept constantly 

 circulating. If the ventilation is sufficiently active the meat will be 

 dry enough in three hours to be ground up in a mill. The powder, 



VOL. XXIII. 40 



