*041 t 
'045 r 
*9/4 z 
' Ohh 4 
'004 . 5 
3 6 Dr. Pearson’s Experiments and Observations 
The whole of this sublimate amounted, by estimation, to 1 8 
grains ; and I apprehend it is the acid sublimate of Scheele. 
The sublimate of carbonate of ammoniac amounted to 20 
grains; and it was black empyreumatic animal oil which 
stained the tube. 
This experiment was repeated, on 120 grains of a nut-brown, 
very light, urinary concretion. The result was not very diffe- 
rent from that of the former experiment, except that the gaz 
contained a portion of hydrogen gaz. There were 30 grains 
of the above described spicula , principally mixed with carbo- 
naceous matter : they were light, and had only a very slight 
sharp and bitter taste. 
The experiment repeated a third time, with 80 grains of 
urinary concretion, afforded 15 grains of the white spicula above 
described, mixed with carbonaceous matter. These I found 
did dissolve in a large proportion of muriatic acid; which solu- 
tion yielded them, on evaporation, in the same state as before. 
Under the flame applied by the blowpipe, they first melted, 
and then evaporated, without any smell; leaving a slight black 
mark. Turnsole was reddened by these spicula. 
In a fourth experiment, I found the white spicula contained 
in the carbonaceous matter united, on boiling, with carbonate 
of soda, as well as with caustic soda ; but, as before, muriatic 
acid precipitated nothing from the solution. These spicula 
could not be dissolved in nitric acid ; nor did the solution of 
them in water become turbid with oxalic acid. Their taste was, 
as before, rather bitter and sharp than sour. A very suffocat- 
ing smell issued forth, on breaking the tube used in this expe- 
riment, but it was not from sulphur, nor from prussic acid. 
