account of which has been lately published, entirely 
depends upon the exclusion of air. This method 
is by filling a vessel of* tin plate or glass with the 
meat or vegetables; soldering or cementing the 
top so as to render the vessel air tight ; and then 
keeping it half immersed in a vessel of boiling 
water for a sufficient time to render the meat or 
vegetables proper for food. In this last process it 
is probable that the small quantity of oxygene 
remaining in the vessel is absorbed : for on opening 
a tinned iron canister which had been filled with 
raw beef, and exposed to hot water the day before, 
I found that the minute quantity of elastic fluid 
which could be procured from it, was a mixture 
of carbonic acid gas and azote. 
Where meat or vegetable food is to be preserved 
on a large scale, for the use of the navy or army 
for instance, I am inclined to believe, that by 
forcibly throwing a quantity of carbonic acid, 
hydrogene, or azote into the vessel, by means of 
a compressing pump, similar to that used for 
making artificial Seltzer water, any change in the 
substance would be more effectually prevented. 
No elastic fluid in this case would have room to 
form by the decomposition of the meat ; and the 
tightness and strength of the vessel would be proved 
by the process. No putrefaction or fermentation 
can go on without the generation of elastic fluid ; 
and pressure would probably act with as much 
efficacy as cold in the preservation of animal or 
vegetable food. 
As different manures contain different propor- 
tions of the elements necessary to vegetation, so 
