180 
VARIETIES. 
I 
Magnesia as an Antidote for Poisoning with Copper. — M. Roncher, in an 
article upon this subject, in the Gazette Medicale de Strasbourg, draws the 
following conclusions, from experiments he has made : 
1st. The calcined magnesia will arrest entirely the symptoms of poison- 
ing with copper, if it be administered sufficiently soon after the copper has 
been taken. 
2d. That the dose of magnesia necessary to neutralize the salt of copper, 
is eight grammes of magnesia to one of sulphate of copper. 
3d. That as magnesia prevents the formation of the greenish, soluble salt, 
it is quite probable that it will act as an antidote to all the salts of cop- 
per. — Southern Med. and Surg. Joam., from Revue Medicale, Aug. 1851. 
A New Method for Preventing Fat and Fixed Oils from becoming Rancid. 
By Charles W. Wright, M. D., of Cincinnati. — In company with one of 
the early settlers of this part of the United States, the conversation turned 
upon the history and habits of the Indians formerly living in this valley, 
and among other things he mentioned the curious manner in which they 
preserved bear's fat from becoming rancid, of which the following is a brief 
account : In the early part of winter the fat is removed from the body of 
the animal and subjected to the trying-out process, as it is termed ; that is, 
it is subjected to a degree of heat sufficient to coagulate and separate the 
azotized matter which subsides to the bottom of the vessel, and the oil is 
drained off. After this operation is completed, it is melted again with the 
bark of the slippery elm tree, (idmus fulva,) finely divided, which may be 
used either in the fresh or dry state. The proportion is about one drachm 
of the bark to the pound of fat. When these substances are heated toge- 
ther for a few minutes, the bark shrinks and gradually subsides, after 
which the fat is strained off and put aside for use. 
The bark communicates an odor to the fat that is hardly to be distin- 
guished from that of the kernel of the hickory nut. 
Thinking this might be turned to account in the preservation of the fatty 
matters, I subjected many of them to experiment, and in every instance the 
result was alike successful. One specimen of butter, (an article which it is 
well known becomes rancid sooner than any other kind of fat,) prepared in 
this way more than a year ago, is as sweet, and as free from disagreeable 
odor, as the day it was made, having been exposed all this time to the 
atmosphere and change of temperature. 
Hog's lard may be preserved in the same manner. 
This fact will be of much importance in the preparation of cerates and 
ointments, which can be thus protected from rancidity. 
In the lubrication of delicate machinery an acquaintance with this fact 
may be of benefit by preventing the injury that results from the use of 
rancid oil. — Western Lancet. 
