Seen I nr na 
(eer 4) 
Geology. A421 
the resinous matter of the Boletus luridus. If the juice happens to be 
deprived of O, the resiniferous solutions will not be colored blue; but 
if it contains O, the solution will assume a blue color, just as if they 
an oxydizing agent. Indeed, that matter may in many respects be 
compared to NO?, which, as is well known, enjoys to an extraordinary 
extent the power of instantaneously transforming O into O, and form- 
°o 
ing a compound (NO2+1.20) with that Q, from which the latter may 
easily be transfered to a multitude of oxydable matters. Now in a 
physiological point of view, the existence of such an organic substance 
is certainly an important fact, and seems to-confirm an old opinion of 
mine, according to which the oxydizing effects of the atmospheric oxy- 
gen (of itself inactive) produced upon organic bodies, such as blood, 
two more. The peculiar matter contained in the juice of the Agaricus 
ce] ; ‘ 
sanguineus, &c., and charged with O, gives up that oxygen to guaia- 
cum, and the latter transfers it to the resinous matter of the Boletus 
luridus ; thus the different organic matters capable of uniting with Oas 
Much engaged my attention. 
II. Grouoey. 
1. Description of two Icthyodorulites, by Joseru Letpy, M.D., ( Proc. 
Acad. Nat. Sci. Philad. vol. viii, p. 11.)—Srenacantuvs nitipus, Leidy. 
i in j rex. The 
the | seal ae: see OF the fovel is furnished with a row of closely set 
serrations, directed obliquely downward, of which eight may be counted 
