CONDITIONS OF PUTREFACTION. 131 



coating, and various materials have been recommended for the 

 protection of spiced or cooked meats. One of the simplest appli- 

 cations of this heating or germ-destroying process is that of 

 instanstaneously dipping eggs in boiling water, coagulating a 

 thin outer layer of albumen, and thus rendering the whole mass 

 incapable of putrefactive change. 



The whole of the foregoing processes serve to confirm Prof. 

 Wyman's observations, and are based entirely on the efficacy of 

 sufficient boiling in the destruction of the germs of decay. 



But let us now for a moment turn to the conditions under 

 which putrefaction most readily supervenes ; and our illustra- 

 tions had better be gathered from the experience of butchers 

 and others handling meats. From the fact that summer is the 

 season when, above all others, animal produce undergoes rapid 

 change, it might be supposed that heat alone was sufficient to 

 excite changes, and there is a vague impression among meat- 

 packers that animal heat is something different from the ordi 

 nary 100° Fahr., and is worse than any other kind of heat. 

 They know that meat in strips hung exposed to a tropical sun 

 dries ; that the buffalo meat which the Indians save, and the 

 charqui of South America, are but illustrations of the preserv- 

 ative power of heat. Heat is there applied so as to dry the 

 meat, and the elimination of moisture tends to make the fleshy 

 fibres indestructible. If, however, a quarter of beef is hung up 

 during hot weather, the surface may dry and remain sound, but 

 the interior turns, and is soon green. 



Even in winter a lot of hogs may be killed in the evening, and 

 whilst still warm packed in carts ready for delivery early next 

 morning. The carcasses buried beneath others heat. The cold 

 hogs remain intact, but the hams of the lower ones taint in 

 pickle. Masses of frozen hams termed " green," in the trade, 

 — that is, which have been a few days in salt, — are sent from 

 the West to New York ; are purchased by provision-dealers ; 

 they are tested, and apparently sound ; but when spring-time 

 comes, and a thaw supervenes, large qviantities of these hams 

 turn. The salt has not penetrated. A putrefying centre has 

 been surrounded by ice ; all has remained stationary so long as 

 the temperature has been low ; but the instant heat supervenes 

 the process advances, and the entire ham turns sour. Ham- 

 curers will tell you that it is the interior of the joints and the 



