114 
Transactions of the 
opaque and granular, or radiatingly fibrous, or expanded into tufts 
of fine needles. And at the end of a week the spheres were alto- 
gether replaced by tufts of needles. 
II. Urate of Ammonia. 
1. Uric acid was digested in liq. ammoniae at 150^ for two 
hours ; left for twenty-four hours at temperature of laboratory ; 
then water being added the mixture was boiled, and filtered. The 
salt was deposited in tufts of fine needles. 
2. The filtrate was evaporated somewhat rapidly to a small 
bulk. It was then discoloured, having a pinkish brown tint, and 
had exchanged its former alkaline for a very decided acid reaction. 
On cooling, it deposited dark brown spheres with strongly-marked 
radiating crystalline tendency within, and an outer layer of dense, 
homogeneous, non-crystalline character. They looked as though 
in a state of tension.. On examining the deposit next day I found 
the spheres all broken up into delicate six-sided plates, rhombs, 
and diamonds, with masses of small, bright, coalescing spheres, mixed 
with small dumb-bells and octohedra of oxalate of lime. There 
was apparently a mixture of uric acid, acid urate, and perhaps 
neutral urate. See Fig. 19, a, h. 
3. With albumen used in many ways I obtained urate of am- 
monia always in the finely molecular form. 
4. Gelatin had the same effect. 
5. A strong hot solution of chloride of ammonium being added 
to a hot solution of urate of ammonia, a large, soft, light precipitate 
was formed at once. It consisted of coarse granules which did 
not sink or run together, being held apart by a gelatinous deposit 
containing very fine needles irregularly arranged. The granules 
were spherular, dumb-bell-shaped and irregular. The deposit had 
not altered when examined after several days. The solution was 
faintly acid. 
6. Hot strong solutions of urate of ammonia and chloride of 
sodium were mixed. The solution was still clear while hot, and 
was faintly acid. Next day a bulky gelatinous precipitate had 
fallen, and filled three-fourths of the fluid. The precipitate was 
composed of bright spheres of various sizes, and bright spheroidal 
granules imbedded in a clear gelatinous stuff. The spheres were 
in appearance a little denser than white blood-corpuscles, and were 
a little more refractile. They looked soft, were easily altered in 
shape without being broken up by compression, and appeared to 
consist of fine molecules. The next day they were all altered, 
being replaced by dense masses of tufts of needles, and small, 
bright, firm, homogeneous spheres. 
This precipitate was thrown on a filter, and washed with dis- 
tilled water. Under the process pf washing it lost its gelatinous 
