222 MEDICAL BOTANY. 



beyond 40°, on the eastern sea board, but at a somewhat higher latitude in the 

 valley of the Mississippi. In both hemispheres the profitable cultivation of it 

 ceases at about 30°, except in elevated situations or in islands. Thus the 

 region of vineyards occupies about 20° in breadth in Europe, but not more 

 than half that extent in the United States. In the southern hemisphere the 

 observations have not been sufficient to ascertain whether the same rule will 

 apply ; though the Cape of Good Hope, where the vine flourishes, would 

 seem to show that it is equally true in Africa. Ainslie states that the grape 

 can be successfully grown in India, but that the climate precludes the making 

 of wine. 



The age to which the vine will attain is very great, and equals, if it does 

 not surpass that of the oak. Pliny speaks of one which had existed for six 

 hundred years, and Bose states that there are vines in Burgundy upwards of 

 four hundred years of age. One growing in England, which was upwards 

 of one hundred years old, covered one hundred and thirty-seven square yards 

 with its branches, and measured four feet in circumference. 



Grapes are usually distinguished by their colours and the shape of the 

 berries, and have been variously classed by different authors. Besides their 

 use as an article of diet, they have been prescribed medicinally ; when .ripe, 

 they are wholesome, antiseptic and cooling, and when partaken of freely, 

 somewhat diuretic and laxative, and have been found beneficial in many dis- 

 eases. In a dried state they are termed Raisins ; these are prepared either by 

 cutting the stalks of bunches half through, and leaving them suspended to 

 the vine until sufficiently dry, or by gathering them, dipping them into a weak 

 ley, and then exposing them to the heat of the sun. What are termed dried 

 currants, are the raisins of a small grape peculiar to some of the Grecian 

 islands, particularly Zante. Raisins are more laxative than the fresh fruit, 

 but are very apt to cause flatulence and colic. They are used in medicine, 

 principally to impart a pleasant taste to certain pharmaceutical preparations, 

 as some of the compound tinctures, &c. 



At onetime almost every part of the vine was recognised as officinal, and 

 considered as possessed of remedial qualities, but are now generally disused ; 

 the leaves, tendrils, and young shoots contain malic and citric acids, and 

 some bitartrate of potash; they are now principally employed in wine countries 

 to flavour vinegar. 



The juice of the grape consists of water, sugar, mucilage, glutinous matter, 

 citric and malic acids, and tartrates of potassa. These principles, when left 

 to themselves for a short time, undergo many important reactions, and their 

 elements assume a new arrangement, and two new compounds are formed 

 wine and acetic acid. 



When the grapes are fully ripe, they are gathered for the manufacture of 

 wine, and in most cases are, as soon as possible, subjected to pressure to sepa- 

 rate the juice from the skin and seeds; for some wines, however, especially 

 those of a rich and luscious character, they are permitted to become partially 

 dried before gathering ; this is practised in making the celebrated Tokay. 

 Several modes are pursued to separate the juice, sometimes, as in Italy, the 

 grapes are placed in perforated tubs over the vat, and trodden with the feet, or 

 they are subjected to the action of a press in hair-cloth bags. The expressed 

 fluid, or must, is then poured into a proper vessel and exposed to a tempera- i 

 ture of at least 55° to enable it to commence the fermentative process. In 

 a short time the liquor becomes turbid, its temperature increases, and the skins, 

 seeds, and other impurities rise to the surface, and carbonic acid is generated. 

 When this fermentation is over, the spongy crust which had formed at top, 

 falls to the bottom, the fluid becomes clear, is found to have lost its former 



