198 H. G. SMITH. 
not from the alteration of malic acid, but rather that it was 
derived from the natural oxidation of butyric acid in the tree itself. 
It is well known that all the fatty acids of the series C,H,,0., 
from butyric acid upwards, when oxidised by nitric acid yield 
succinic acid, together with other acids of the same series. Its 
formation from butyric acid is represented by the equation 
(C,H,0,+0, =H,0+C,H,O,).! Many organic substances 
that are oxidised to butyric acid by nitric acid, generally yield 
succinic acid also, notably agaricic acid, from the Larch fungus 
(Boletus Laricis ), which by oxidation with HNO, gives both acids.” 
Normal butyric acid is widely distributed in the vegetable 
kingdom. It has been detected in croton oil, and other fatty 
vegetable oils; in tamarinds; in the fruits of the soap-nut tree, 
and that of the Gingko biloba, Linn.* Iso-butyric acid also occurs 
in many vegetable substances. It occurs free in the flowers of 
the Arnica montana, as well as in the Carob bean ( Ceratonta 
siliqgua,) and among the acids of croton oil.‘ 
The presence of butyric acid in rotten potatoes was demons- 
trated in a paper read by Mr. J. R. Rogers® in 1846, and from 
the method by which it was obtained, it must have existed as 
free butyric acid. 
Although its presence in the vegetable kingdom is thus well 
authenticated, yet, I have not found that butyric acid has pre- 
viously been detected in the sap of any tree. 
_I have no evidence as to the form in which the acid is present, 
whether as normal or as iso-butyric, but the odour is less 
unpleasant than that obtained from the decomposition of butter, 
so that if the sap is further investigated it may perhaps be proved 
to be iso-butyric acid. 
1 Watts’ Dict. Chem., 1879 Edition, Vol. v., p. 453. 
2 Watts’ — nape ertewn & ee en I., p. 87.- 
ee try, Vol. m1., pt.i., p. 591. 
SUL ys 
4 Op. cit. p. 599. 
5 Pharm. Journ. Vol. v., p. 345. 
