NITRATE OF SODA DEPOSITS OF SOUTHERN PERU. 
225 
of iron with about half a drachm of syrup, until reduced to a smooth 
paste, afterwards adding the carbonate of soda, rubbing until the 
decomposition is finished, and lastly adding the myrrh and incorpo- 
rating it. The use of the unpowdered myrrh will be found to give 
a peculiar consistence to the mass, arising from the intimate ad- 
mixture of the oleo-resinous particles with the salts. 
Mistura Amygdala. Mr. Canavan proposes, instead of keeping 
the solid ingredients of this mixture ready mixed as recommended 
by the PharmacopcEia, that the almonds be preserved for use after 
being blanched and well dried, in which state they are not liable 
to change as w 7 hen the kernel is beaten into a paste with sugar and 
gum. 
Liquor Potassce Arsenitis. In a note on this subject Mr. Cana- 
van states that a shop bottle of Fowler's solution, which had been 
kept some six or twelve years, exhaled a strong garlicky odor char- 
acteristic of free metallic arsenic. The interior surface of the bottle 
was found to be corroded, and possessed a metallic lustre which 
Mr. Canavan considered to be metallic lead, eliminated from the 
flint glass by the action of the solution ; as it was slowly acted 
upon by acetic acid it yielded iodide of lead with iodide of potas- 
sium. This is a curious fact, probably due to the excess of alkali 
in the arsenite. We do not understand where the garlicky odor 
came from, as it is only the vapor of metallic arsenic that possesses 
this peculiarity. 
ON THE NITRATE Or SODA DEPOSITS OF SOUTHERN PERU. 
In the twenty-first volume of the Journal of the Royal Geo- 
graphical Society, is a descripton of the province of Tarapaca, in 
Southern Peru, from which the following account of the deposits 
of nitrate of soda is taken. 
" The existence of this valuable substance in the province of 
Tarapaca, has been known in Europe about a century. In 1820, 
some of it was sent to England, but the duty then being so high, 
it was thrown overboard. In 1827, efforts were unsuccessfully 
made by an English house to import it. In 1830, a cargo was 
sent to the United States ; it was found unsaleable there, and a 
