112 The American Naturalist. [February, 
wanting in muscle tissue, poor in nuclei. F. Kronecker" 
found it in the spleen, lymph glands and kidneys of oxen, 
while Stadthagen” found it present in the liver and urine of a 
patient suffering from leukemia, a disease in which the white 
blood cells are enormously increased in number. It is not to be 
understood, however, that the adenin exists wholly free in 
these cases. On the contrary, it exists in plant and animal 
tissues in loose combination, in part at least, with albumin 
and phosphoric acid. This combination is easily broken by 
the action of dilute acids, especially at 100° C., and also by 
spontaneous decomposition after death, i. e., the adenin is 
an integral part of the nucleic acid which is present in all cell 
nuclei, and under certain conditions can be split off from the 
complex molecule of which it is an integral part. ; 
In composition, adenin is peculiar in that it contains n0 
oxygen. It is composed solely of carbon, hydrogen and nitro- 
gen in such proportion as to warrant the conclusion that it 18 
a polymer of prussic acid, HCN. It has in fact the same pèr- 
centage composition as prussic acid, and its ready convert 
bility into potassium cyanide by fusion with caustic potash at 
00° C., testifies to the close relationship between these two 
bodies. The existence of cyanogen compounds in the animal 
body has long been suggested as theoretically probable, and 
the finding of adenin gives to this hypothesis a substantial 
basis and points to the cell nucleus as the seat of these cya2® 
gen compounds. Further, adenin is closely related to hypo* 
anthin, a body with which we are more familiar and whose 
origin we shall need to consider. Moreover, we find when "° 
come to study relationships that all the so-called nuclei 
bases are closely related to adenin, as is seen from the follow 
ing formule, which bring out the analogies quite clearly: 
Adenin CLN, NH Guanin C,H.N.O ne 
Hypoxanthin  C,H,N, O Xanthin C,H,N,O 
Both adenin and hypoxanthin contain a peculiar chemical 
group O,H,N,, called by Kossel and Thoiss" adenyl, and W° 
4 Virchow’s Archiv. Band 107, p. 207. 
15 Ibid. Band 109, p. 390. 
Zeitschrift fiir physiologische Chemie, Band 13, p. 396. 
