I 248 ] 



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 can- 

 ister 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 ves- 

 sel 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 they 

 require a different treatment to enable them to pro- 



