232 ESSAY XXL 



method keeps very long, it is not much employed ; probably, 

 because it is troublesome to fill the bottle immediately again, 

 every time you have made use of part of its contents, with 

 clear vinegar from another bottle ; after which, the vinegar in 

 the bottle that is not full, and to which consequently the air 

 has access, soon grows turbid and vapid. The fourth method 

 is to distil the vinegar. Such vinegar suffers not the least 

 change, though exposed to a warm air for years ; but, being 

 more expensive than that which is not distilled, this method 

 is seldom made use of, especially as the following method to 

 preserve vinegar is the easiest of all : 



It is only necessary to put your vinegar into a well- tinned 

 kettle, and make it boil for a quarter of a minute over a 

 strong fire. It is then to be immediately bottled carefully ; 

 or, if any one should be afraid of tin being pernicious to 

 health, he may fill his bottles first, and then put them into a 

 kettle full of water upon the fire. After the water has 

 boiled for about an hour's time, the bottles are taken out of 

 the pot and corked. The vinegar thus boiled keeps for 

 several years, as well in open air as in half -filled bottles, 

 without growing turbid or mucilaginous. It likewise may be 

 used with advantage for pharmaceutical purposes, instead of 

 common vinegar ; for the preparation of the compound 

 vinegars, which, if not prepared with distilled vinegar, soon 

 grow turbid and lose their acidity. 



