7m 
Supplement to the '* Tropical Agriculturist." [M»y 1, 1894. 
TJH3 EEODUGTS OF TUB GEAPE VINE 
AND THEIR USES. 
Gh-apes. — The vine is generally cultivated for 
thfi sake of its agreeable sub-acid fruit, the chief 
acid in which is the tartaric — the tshme as is 
present in the tamarind. Grapes exert a cooling 
and refreshing influence upon the blood, and, like 
many other fruits, have a beneficial effect upon 
the stomach and the liver. The late Mr. A. M. 
Ferguson once wrote as follows about the use of 
grapes in the dessert : — " For those diseases of 
the digestive functions to which dwellers in our 
hot, moist climate are especially liable, ' the grape 
cure ' is frequently prescribed. A full supply of 
grapes at meals might act as a preventive of the 
disease indicated by sore mouth." The follow- 
ing is the percentage composition of the ripe 
gfttpe as given by Dr. Edward Smith : — 
Soluble Parts. 
Grape Sugar . . 13'80 
Tartaric and Malic Acids . . V12 
Nitrogenous matter . , . . "80 
Gum, Fat, &c. . . . . oO 
Salts . , . . . . -36 
Water . . . . 79-80 
Insoluble Parts. 
Skin, Stones, &c. .. .. 2-6U 
Pectose . . . . . . '90 
MineraJ ma^tor. . . . . '12 
10000 
Before they are ripe grapes are extremely harsh 
and sour to the taste, and by expression furnish a 
liquor known as verjuice and formerly used as 
the juice of lemons. Among other substances, 
verjuice contains malic acid and bitartrate of 
potash. 
A vinegar is obtained, though rarely, from 
grapes. It is variously used as a condiment, for 
extracting the virtues of other medicines, and for 
counteracting the effects of vegetable poisons. 
It is said that an excellent vinegar can also be 
made from the loppings and pi unings of the vine. 
The bitartrate of potash or cream of tartar 
which is deposited during the fermentation 
of wine is used as an aperient. 
Maisins. — As the grape is being dried, the 
quaatity of sugar in it increases, while that of 
malic acid diminishes. Raisins are, therefore, 
more saccharine, but less cooling and refreshing 
than grapes. There are many sorts of raisins. 
The " muscatels " which are highly prized for 
dessert are left to dry in the sun hanging on the 
vine itself and are hence called sun raisins. The 
leaves around being first cut off, the bunches are 
left undisturbed until the grapes are sufficiently 
dried and converted into raisins. These are the 
lftrg«st and sweetest raisins in the market and 
sell at high prioes* The " Sultanas " are the 
snMbliest w^ioh ar« sold under the name of raisins 
and are of a peculiarly fine flavour. The former 
grow in Southern Europe and the latter in 
Turkey. It is thought that the quality and ap- 
pearance of ordinary raisins can be improved by 
dipping them in lye before being dried, Curraiits 
are-prepared from- a small, seedless variety of 
grapes. They are less juicy and contain a less 
proportion of sugar than the muscatels. The 
cbief use o{ raisina aod currants ie iu the pre- 
paration of puddings, but wine is also bosatstimet 
obtained from them. 
Wine. — Must is the unfermtioted grafte juioa, 
Wine is the juice of the grape altered by fermen- 
tation. The quality of wine dei>ends principally 
on the proportion of sugar contained in the must, 
I and the manner of its fermentation. M^hen tlie 
I quantity of sugar is sufficient and the fermenla- 
I tion complete, the wine is perfect iu quality. If 
the quantity of saccharine matt«r be too large, 
the fermentation is slow and consequeutly part 
remains undecomposed imparting n swtttst 
and luscious taste to the wine. On tlie other 
hand if there is too little sugar in the mui-t, the 
wine is thin and weak, t^eylou-grown grapee 
are sometimes found deficient in saccharine 
matter. Father Assauw, writing from Wahakotte, 
says: — " 1 tried to make wine out ot grape* grown 
here, but I had to add from 3 to 4 oz. of bugor 
to each bottle before I could have got anytliiug 
like wine." If the skin of the grape is remorejl 
from the must before the fermentation sots iu, 
the wine has little or no c>lour and is called 
white wine. If, on the contrarj-, the hkin if 
allowed to remain in the juice while the fermen- 
tation is going on, tJie alcohol dissolves the 
colouring matter of the skin, and the wine 
assumes a red colour. Some of the red wines, 
such as Port, contain tannic acid derived from 
the skin. 
Oil from the -Seeds. — A useful oil is extracted 
from the grape stones in some places. In order 
to separate the seeds from the husks and other 
refuse matter, the mash is put into a bucket with 
.some water and worked about with the hands 
until the seeds sink to the bottom. They are 
then removed and dried in the sun as soon as 
possible. AVhen a sufficient quantity is collected, 
the whole is ground in an oil mill. The oil 
which is then cold drawn is scarcely distinguish- 
able from common olive oil. The oil cake that it 
left in the mill as residue, when scalded in a little 
hot-water, yields a fresh portion of oil, which 
though inferior to the cold-drawn oil first ob- 
tained, bums excellently well in a lamp, giving 
out no impleasant odour and verj' little smoke. 
B. T. flOOLE. 
DAIET PICKINGS. 
Milk, as is well-known, after being taken from 
the cow, placed in vessels, and left undisturbed 
at the ordinary temperature, becomes sour, loses 
its liquid character, and is ultimately conTerted 
into a gelatinous mass. If this mus.s be broken up 
by raising the temperature it will separate into 
curd, which is caseine and fat, and a bright liquid 
whey. This change of souring and coagulation, 
says Professor M'ConnelJ, a well-known English 
authority, is caused by the action of a living 
ferment or micro-organism called the lactic fer- 
ment, which enters the milk from the atmosphere 
after the milk has been taken from the cow. 
The rapidity with which the ferment acts depends 
on the temperature of the milk. It acts verj- 
t^uickly at the temperature at which milk leaves 
the cow — 90*^ Fahr., the maximum rapidity 
being attained at 100° Fahr. At 114° the action 
ceases altogether, the heat being too great 
for the ferment. Oa tbe other baud, tbe ferment 
