VIN 



the mean produce of the vine for the 

 Avhole of France as 170 9 gallons per 

 acre, state the whole of the wine pro- 

 duced over the country at 976,906,414 

 gallons." — {BoussiiigauU.) 



VINEGAR. "This term is ap- 

 plied to various modifications of the ' 

 acetic acid. The simplest mode of 

 obtaining vinegar is to excite a sec- 

 ond or acetous fermentation in wine, 

 beer, or cider. In this case o.vygen is 

 absorbed, a variable projjoriion of car- 

 bonic acid is generally evolved, and the 

 alcohol of the wine passes into acetic 

 acid. Very good vinegar is also made 

 from a wort or infusion of malt pre- 

 pared for the purpose, or from a de- 

 coction of common raisins, or from a 

 mixture of about one part of whis- 

 key w-ith eight of water, and some 

 sugar and yeast. See Cider. 



"When vinegar is distilled, various 

 impurities which it contains remain 

 in the still, and the liquid which pass- 

 es over is the acetic acid, nearly 

 pure, but largely diluted with water. 

 In this state it is usually called dis- 

 tilled vinegar, and is chiefly used in 

 pharmacy ; but the market is chiefly 

 supplied from another source, which 

 is the destructive distillation of wood. 

 It has long been known that when 

 certain kinds of dry wood, especially 

 beech and such woods as are not 

 resinous, instead of being burned in 

 the open air, are converted into char- 

 coal in close vessels, so as, in fact, 

 to be submitted to distillation, that 

 the vapours which pass off yield, 

 when condensed, a large quantity of 

 tar and of very acid water : the lat- 

 ter is, in fact, an impure vinegar. 

 When this unpure acetic acid is freed 

 from the tar and empyreumalic oils 

 with which it is mixed, it is called 

 crude pyroltgncous acid. To convert 

 it into pure acetic acid, that is, to 

 separate from it the empyreumalic 

 products with which it is intimately 

 combined, is a somewhat circuitous 

 process. It is first distilled, by which 

 ■pyroxUic acid and oil of tar first pass 

 over, and these are tbUowcd by a 

 quantity of impure or rough acetic 

 acid. This rough acid is used by dy- 

 ers and calico printers, and by ma- 



4 A2 



VIT 



kers of sugar of lead. The pure ace- 

 tic acid, in its most concentrated state, 

 is extremely acrid, sour, and pun- 

 gent, and is often called radical vine- 

 gar, or, when perfumed, aromatic vin- 

 egar; it is also occasionally termed 

 glacial acetic acid, from its property 

 of congealing at a low temperature, 

 and remaining frozen at temperatures 

 below 50". In this state it is a com-« 

 pound of] atom of real acetic acid =: 

 51, and 1 of water = 9, the real or 

 anhydrous acid, as it exists in the 

 dry acetates, being composed of 



Carbon 4 



Hydrogen 3 



O.xyg-en 3 



" When this strong acetic acid is 

 diluted with water and slightly col- 

 oured, it forms a very pure and ex- 

 cellent substitute for common vine- 

 gar, and is cheaper than acid of the 

 same strength prepared in any other 

 way. 



" The combinations of acetic acid 

 with various bases are called acetates; 

 and of these salts some are impor- 

 tantly useful in the arts : such, espe- 

 cially, are the acetates of lead, copper, 

 iron, and alumina, which are chiefly 

 employed in dyeing and calico print- 

 ing ; the acetates of ammonia and of 

 potash, which, as well as acetate of 

 lead, are used in medicine ; and the 

 acetates of lime and of soda, w'hich 

 have been mentioned as steps in the 

 preparation of strong acetic acid. The 

 acetates are recognised by their sol- 

 ubility in water, and by the fumes of 

 acetic acid which they evolve when 

 acted upon by sulphuric acid. The 

 specific gravity of the strongest liquid 

 acetic acid is 10629 ; that of good 

 malt vinegar is lOCOO ; and that of 

 distilled vinegar about 10023. The 

 strength or value of vinegar, and of 

 acetic acid, can only be learned by its 

 saturating power." 



V I N E \^ A II D. A plantation of 

 grapes. The vines are set in rows, 

 four to six yards apart, and usually 

 sustained against trellises or stakes. 



VIOLET. The genus Vwla, of 

 which V. odoratu is the perfumed vio- 

 let, and V. tricolor the heart's ease. 



VITELLUS. An occasional cov- 



833 



