126 BOARD OF AGRICULTURE. 



Times" to say, in 1865, that I was as irrepressible as the cattle- 

 plague itself, I trust to merit the honor of such an encomium 

 on all occasions whensoever or wheresoever the cause of truth 

 finds in me an humble exponent and defender. 



But to return to the theory of spontaneous generation. It 

 was assumed by many thinking men until recently that organic 

 products, complex in their structure and chemical constitution, 

 had an inherent tendency to resolve themselves into simpler 

 compounds, and that the affinity which held the elements to- 

 gether in life was lost at once and forever in death ; that the 

 rapidity of these post mortem changes might be checked, and 

 that modifications in the results of ordinary decompositions 

 might be obtained. The air which, on the one hand, is known 

 to sustain life, that air, breathed into us with the breath of life, 

 has been viewed as an active agent in putrefaction, and crude 

 ideas have often been expressed to me regarding the identity 

 between decay and simple oxidation. It is rare to find a meat- 

 packer who knows that meat will putrefy in vacuo. If I take a 

 vessel into which meat is placed, introduce at the same time 

 some charcoal charged with sulphurous acid, in sufficient 

 amount only to seize the oxygen of the residuum of air left 

 after exhaustion by a good pump, and attend with scrupulous 

 care to the tightness of the vessel, and all other conditions cal- 

 culated to avoid fallacy, the meat thus treated putrefies much 

 more rapidly than a piece of meat hung up in the open air. 

 Nay more, if the experiment be varied by saturating the meat 

 with carbonic-oxide gas, as a means of expelling the oxygen, 

 and even use bin-oxide of nitrogen, instead of the charcoal and 

 sulphurous acid, so as to deprive the air completely of its 

 oxygen, provided the amount of bin-oxide be not in excess, 

 the meat putrefies more rapidly than a piece subjected to atmos- 

 pheric currents. Oxygen is not necessary, therefore, to start 

 and maintain decomposition. 



Not only, however, does meat hang longer unchanged in the 

 open air, but the ordinary process of canning cooked meats 

 leads daily to the repetition, ad infinitum, of a simple experi- 

 ment which any one can make with a Florence flask. If a piece 

 of meat be placed in such a vessel and boiled steadily at 212° 

 or a little higher for five or six hours, and the neck of the bottle 

 then hermetically sealed with a blow-pipe, it will be found that 



