447 



Tf might appear singular, that death should aftorcl a just idea of life, 

 did we not know that it is by comparing, that we are enabled to distin- 

 guish, to judge, and to arrive at knowledge*. 



Putrefaction takes place and is completed, only in substances deprived 

 of life. A mortified limb loses its vitality, before putrefaction comes on; 

 and if nature preserve sufficient energy to resist this destructive process, 

 she draws, by a line of inflammation, the separation between the dead 

 and the living part. Life and putrefaction are, therefore, two absolutely 

 contradictory ideas ; and when, in some diseases, there is observed a ten- 

 dency in solids and fluids to spontaneous decomposition, this tendency to 

 putrefaction should not be mistaken for putrefaction itself. 



Several conditions are required to enable putrefaction to affect the hu- 

 man body after death. In the first place, a mild temperature, that is, 

 above ten degrees of Reaumur's thermometer ; in the next place, a cer- 

 tain degree of moisture; and lastly, the presence of air. This last con- 

 dition, however, is not so necessary as the two former, since substances 

 undergo putrefaction in a vacuum, though more slowly. The air conse- 

 quently promotes a decomposition, only by carrying off the element which 

 rises in vapours. On the other hand, an icy cold, or a degree of heat ap- 

 proaching to boiling, prevents it; the former, by condensing the parts ; 

 the second, by ""depriving them of moisture, the complete absence of 

 which, accounts for the preservation of the Egyptian mummies. 



The phenomena of putrefaction, resulting from a series of peculiar at- 

 tractions, are modified in various ways, according to the nature of the 

 animal substances which are subjected to it, to the media in which it 

 takes place, to the different degrees of moisture and temperature, and 

 even according to its different periods. Notwithstanding these innume- 

 rable varieties, one may say, that all exhale a certain cadaverous smell, 

 are softened, increase in bulk, acquire heat, change colour, assume .a 

 greenish, then a livid and dark brown colour 5 there are, at the same 

 time, disengaged a great number of gaseous substances, of which ammo- 

 nia is the most remarkable, either from its quantity, or from being given 

 out by animal substances, from the moment when decomposition begins, 

 to the period of the most complete dissolution. This gas produces the 

 pungent and putrid smell which exhales from dead bodies. 



Towards the termination of putrefaction, there is disengaged carbonic 

 acid gas, which, combining with ammonia, forms a fixed and crystalliza- 

 ble salt. Besides these products, there are given out sulphuretted and 

 phosphoreited hydrogen, or combined with azote, carbonic acid, and all 

 the substances which may be produced by their respective combinations. 

 In the last place, animal substances, when reduced to a residue containing 

 oils and salts of different kinds, form a mould, from which plants draw 

 the principles of a luxuriant and vigorous vegetation. The bones, those 

 least alterable parts of the organized machine, in time, become dried by 

 the slow combustion of their fibrous part, and by the evaporation of their 

 medullary juices. At last, reduced to an earthly skeleton, they crumble 

 into dust, and this dnst is dissipated, on opening the tombs in which they 

 were laid. 



Thus, in the course of time, is effaced all that could recall the idea of 

 our physical existence. 



* See APPENDIX, Note M M^ for some remarks on the signs of deatk 



