ON THE FOOD-VALUE OF THE KOLA-NUT. 
450 
ruination, accomplished by kneading the thoroughly powdered nut in a fine calico 
bag under a stream of water, a process by which the starch is washed out into a 
receiving vessel, and the cell-wall remains in the bag, showed that starch, dried 
at 212° F., is present to the extent of 42*5 per cent., and cell-wall and colouring- 
matter to the amount of 20 per cent. Kola-starch granules are of about the 
same size as those of wheat, namely, from one thousandth to one ten-thousandth 
of an inch in diameter, but are readily distinguished by their action on polarized 
rays of light, which they so affect as to be apparently traversed by a black or 
white cross, whose four arms meet at the hilum in the centre of the granule, the 
beauty of the effect being of course enhanced when a plate of selenite is placed 
beneath the object in the path of the ray. The colouring matter of the cell-wall 
of the nut is soluble in alkaline solutions, yielding reddish-yellow solutions. 
Then, again, Kola resembles coffee in containing a small quantity of a fragrant 
aromatic volatile oil, having a burning, persistent, penetrating taste. In the 
case of Kola the odour closely resembles that of myrrh. Probably, as in coffee 
and tea, some of the activity of Kola is due to this volatile oil. Kola also con¬ 
tains a fixed fatty matter, the fat and oil being dissolved out of the powdered 
nut by ether to the extent of 1^ per cent. In coffee there is 10 to 12 per cent, 
of fat, while tea has none. There is 1*56 per cent, of nitrogen in dried Kola- 
nut. Subtracting from this number *56, which is the amount that belongs to the 
Theine, there is left 1 per cent., which appears to exist in the form of 6*33 per 
per cent, of an albumenoid substance resembling legumin, one of the so-called 
liesh-forming materials. Kola can, however, be but of little value as a flesh¬ 
forming article of food, because apparently the juice only of the nut is swallowed : 
the more solid part, which would of course contain nearly the whole of this ni¬ 
trogenous matter, being rejected. Moreover, unless the natives consume very 
much more of Kola than we do of coffee, the total amount of flesh-forming ma¬ 
terial they would eat at a meal, even if they swallowed the whole of the nut, 
would be too small to be worth taking into consideration as a constituent of food. 
Coffee contains 13 per cent, of this nitrogenous matter, and tea about 22, but 
in our methods of making beverages from these two substances, scarcely any of 
it is swallowed, it remaining as valueless along with the spent leaves and frag¬ 
ments. The ash obtained on burning Kola is 3*2 per cent., about half the amount 
that coffee or tea yields. It resembles the ash of coffee and tea in being com¬ 
posed of chlorides, sulphates, and phosphates of potash, lime, and magnesia. The 
greater part of the phosphoric acid is in the soluble condition, probably combined 
with potash or ammonia, and would of course be swallowed with the juice on 
chewing the nut. Gum, sugar, and other organic matters, the nature of which 
could not be determined, are present to the extent of 10*67 per cent., a proportion 
similar to that in coffee and tea. Finally, the common astringent principle 
tannin, which occurs in coffee to the amount of 5 per cent, and in tea to 15 per 
cent., and which gives to tea and coffee beverages their pleasant rough taste, is 
entirely wanting in Kola. 
The following is a tabular form of the composition of dry Kola-nuts :— 
In 100 parts. 
-i o i » r? 
Water. 
Cell-wall and colouring 
matter 
. . . 20 00 
Starch. 
. . . 4-2*50 
Volatile Oil . 7 
Fixed Fat . J> 
Albumenoid substance 
p oo 
Gum. 
h 
Sugar. 
f 
. . . 10*67 
Other organic matter. 
3 
Ash. 
Theine 
2*13 
