444 Miscellaneous Intelligence. 
which does not act on the other substances. The action of the 
alcohol is repeated twice, or till it acquires no bitter taste. 
The sediment is subjected to the press. The alcohol is filtered, 
and then distilled off in a water-bath. There remains in the 
retort a very small quantity of a deep-coloured liquid, and a 
substance in the form of brilliant crystals. These are strych- 
nia, containing a colouring and oily matter; if it be treated 
several times with alcohol, we obtain it very pure. It is indeed 
more expeditious to form an easily erystallizable salt with it, 
for which purpose dilute nitric acid is preferred by M. Henry. 
The nitrate solution, after concentration, is treated with animal 
charcoal at a boiling heat, and quickly filtered. On cooling, 
the salt forms in slightly-coloured crystals, which can be pu- 
rified by solution and re-crystallization. 
To obtain strychnia from this salt, we pour into its solution a 
slight excess of ammonia, when the vegetable alkali precipitates 
in awhite powder. The nitrate must be dissolved in the least 
possible quantity of water, as the strychnia itself being some- 
what soluble, a portion would be left in the liquid. 
The whole strychnia may be separated from the mother waters 
by concentrating them, and adding anew pulverized quicklime, 
and then treating the mass with alcohol. One kilogramme of 
pulverized nux vomica yields from 5 to 6 grammes of strych- 
nia.—Jour. de Phar., Sept. 1822. 
22. Smalt in Sugar.—It appears from a note in the Journal 
de Pharmacie for October last, that the Parisian refined sugar 
contains sometimes a notable quantity of smalt, which falls to 
the bottom of the vessel in which that substance is dissolved. 
As the cobalt ore from which smalt is made generally contains 
arsenic, this sophistication is justly reprobated. 
23. On the Employment of Potatoes in Steam-Engine and 
other Boilers, to prevent the calcareous Incrustations on their 
Bottoms and Sides.—The practice of adding about | per cent. of 
potatoes to the bulk of water contained in a steam-engine boiler, 
which has been long practised in this country, has been re- 
cently introduced into France, and merits the encomium which 
is bestowed on it by M. Payen, in a letter to the Editor of the 
Jour. de Phar., Oct. 1822. He assigns the true cause of the 
beneficial agency of the root. The potato dissolves in the 
boiling water, forming a somewhat viscid liquid, which enve- 
lopes every particle of the precipitated calcareous salt, (usually 
selenite, sometimes carbonate of lime,) renders them slippery, 
so to speak, and prevents their mutual contact and cohesion. 
After a month’s service, the boiler is emptied, and new potatoes 
added along with the charge of water. 
24. On the manner of estimating the Quantity of Sulphuretled 
a 
