MISCELLANY. 
Phosphorus Paste for the destruction of Rats and Mice. By M. Simon, 
of Berlin. — The Prussian government issued an ordonnance on the 
27th of April, 1843, directing the following composition to be substituted 
for arsenic, for destroying rats and mice; enjoining the authorities 
of the different provinces to communicate, at the expiration of a year, 
the results of the trials made with it, with the view of framing a law 
on this subject. 
The following is the formula for this paste, as published in the 
Berliner Medicinische Zeitung : 
Take of phosphorus 8 parts, liquify it in 180 parts of lukewarm 
water, pour the whole into a mortar, and add immediately 180 parts 
of rye meal; when cold, mix in 180 parts of butter melted, and 125 
parts of sugar. 
If the phosphorus is in a finely divided state, the ingredients may 
be all mixed at once, without melting them. 
This mixture will retain its efficacy for many years, for the phos- 
phorus is preserved by the butter, and only becomes oxydized on the 
surface. 
Rats and mice eat this mixture with avidity ; after which they swell 
out, and soon die. 
M. Simon, has employed this mixture for many years, with 
constant success, by placing it in places frequented by those animals. 
According to him, the phosphorus is less dangerous than arsenic, for 
supposing the mixture to be badly made, and the phosphorus imper- 
fectly divided, the oxydation which would take place in a few days 
would render it nearly inactive ; and it would be almost impossible to 
employ it for the intentional poisoning of human beings. — Pharm. Jour, 
from Jour, de Chim. Meet 
Fizeau's process of etching Daguerreotype Plates and its application to 
objects of Natural History. By Mr. Goadby. — In a Daguerreotype 
portrait, the black parts of the plate consist of silver, the white of mer- 
cury, and the intermediate tint of a mixture of the two, the degree of 
darkness or light depending upon the excess either of the silver or of 
