S. W. Johnson on Assimilation of bodies by Vegetation. 27 
If such, having the crystalline character of mica or asbestus, 
could be added a valuable product might result. 
eydolt observed in a slag (see his No. 7) cubic crystals of 
nearly the same color as the glass and visible to the eye e 
could ascertain the nature of the glass crystals as well as that of 
the matrix (which may also be crystalline) possibly we might, 
by the laws of isomorphism, be able to color the crystals at will, 
thus producing new and beautiful effects in articles of glass-ware. 
In this connection Leblane’s observation of protoxyd of iron in 
the transparent portion and but traces of this base in the crys- 
talline part of a specimen of glass, may be noted. 
The detection of the crystalline nature of glass demonstrates 
that we are as yet unacquainted with the true character of this 
complex substance; but at the same time it indicates the path to 
be pursued for acquiring this desirable knowledge. 
Art. V.—Contributions from the Sheffield Laboratory of Yale 
College. No. IX.—On the assimilanon of complex nitrogenous 
bodies by Vegetation ; by S. W. JOHNSON. 
Durine the summer of 1861 the writer undertook a series of 
observations on the nutrition of plants, which, though a failure 
as regards the principal object of the investigation, led to some 
interesting results. sides various inorganic matters, the nitro- 
genous compounds oceurring in urine which may be directly 
applied to crops as fertilizers, viz: urea, guanine, uric acid and 
ippuric acid, were intended to be made the subjects of experi- 
ment. 
Washed and ignited flower-pots (of clay, unglazed) were em- 
ployed to contain, for each trial, a soil consisting of 700 grms. of 
& istae and washed granitic sand mixed with 0°25 grm. sulphate 
or lime, 2 grm. ashes of hay prepared in muffle and 2°75 grm. 
bone-ashes. This soil was placed upon 100 grms. of clean gravel 
to serve as drainage. : : ; 
each of several pots containing the above soil was deposited 
July 6th, a weighed kernel of maize. The pots were watered 
with equal quantities of distilled water containing a. scarcely 
preciable trace of ammonia. But four seeds germinated in a 
healthy manner, the plants developed slowly and alike until 
July 28th, when the addition of nitrogenous matters was begun. 
: To bs no solid addition se —_ es : 
9 No. 2, was added July 28, 0°420 grm. uric acid. 
_To No. 8, was added 1-730 grm. hippuric acid, at four differ- 
6th, On. rene aly. 2 28, 0-858 grm., Aug, 26th, 0:358 grm., Sept, 
To No. 4, was added 0-4110 rom hydrochlorate of guanine, 
