THE TECHNOLOGIST [April 1, 1885. 



426 FOOD-VALUE OF THE KOLA-NUT. 



do for the system is not yet very well made out. Liebig thinks that it 

 may aid in the formation of that substance, a normal quantity of which 

 is so necessary, and an abnormal so unpleasant— namely, bile. Most 

 chemists agree that it arrests that rapid consumption of tissue and con- 

 sequent feeling of fatigue which we all experience when we work hard 

 with mind or body. Whatever may be its exact office, its discovery in 

 Kola must greatly enhance its physiological interest, showing, as it does, 

 that the instinctive desire for it in one form or other by Europeans, 

 Americans, and Asiatics, is shared by the natives of Africa. 



The other constituents of dried Kola-nut also indicate that it has the 

 character cf coffee, though differing from that article of diet in some im- 

 portant respects. Thus, on examining some finely powuered-coffee 

 under the microscope, but few or no granules of starch are to be seen ; 

 while the powder of Kola is, apparently, one half starch, the granules 

 forming the prominent object enclosed by the brownish yellow-coloured 

 cell-walls of the tissue. A rough quantitative determination, accom- 

 plished 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 percent. 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, 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 solu- 

 tions. Then, again, Kola resembles coffee in containing a small quantity 

 of a fragrant aromatic volatile oil, having a burning, persisting, pene- 

 trating 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 contains a fixed fatty matter, the fat and oil 

 being dissolved out of the powdered nut by ether to the extent of l£ per 

 cent. In coffee there is 10 to 12 per cent, of fat, while tea has none. 

 There is T56 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 633 per 

 cent, of an albumenoid substance resembling legumin, one of the so- 

 called flesh-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 con- 

 tain nearly the whole of this nitrogenous matter, being rejected. More- 

 over, unless the natives consume very much more of Kola than we do 

 of coffee, the total amount of flesh-forining material they would eat at a 



