CHYMIFICATION. 581 



the term, and this applies particularly to the cold-blooded animal, which 

 must digest, if not with the same, with due, rapidity. 



2. Putrefaction. The next great hypothesis was that of putrefac- 

 tion^ which, we are informed by Celsus, 1 was embraced by Phstonicus, 

 a disciple of Praxagoras of Cos, who flourished upwards of three hun- 

 dred years before the birth of Christ. Of late, it has had no advocates, 

 but appears to have been the view embraced by Cheselden. 2 The rea- 

 sons, urged in favour of it, have been; the putrescible character of 

 the materials employed as food; the favourable circumstances of a heat 

 of 98 or 100, and of moisture; and, by some, the foetor of the ex- 

 crements. The objections are, 1. That when the contents of the sto- 

 mach are rejected, during chymification, they exhibit no evidence of 

 putridity. 2. That in all the experiments, which have been made on 

 the comparative digestibility of different substances, when it has been 

 necessary to kill the animals at different stages of the digestive pro- 

 cess, there has not been the slightest sign of putrefaction. 3. That 

 opportunities frequently occur, for witnessing ravenous fishes and rep- 

 tiles with an animal or portion of an animal, too large to be entirely 

 swallowed, partly in the stomach, and the remainder in the gullet and 

 mouth. In these cases, where the food has remained in this situation 

 some days, the part contained in the throat has been found putrid, 

 whilst that in the stomach has been entirely sweet; and lastly, in Spal- 

 lanzani's and other experiments, to be detailed presently, it was found, 

 when food, in a state of putridity, was taken into the stomach, or mixed 

 with the gastric juice out of the stomach, that it recovered its sweet- 

 ness. It has been already observed, that it is the custom, in some 

 countries, to eat the gibier or game in a state of incipient putrefaction ; 

 yet the breath is not tainted by it. 



3. Trituration. The mathematical physiologists, Borelli, 3 Hecquet, 4 

 Megallotti, 5 Pitcairne, 6 and others after the example of Erisistratus, 7 

 attempted to refer the whole process of digestion to trituration, ima- 

 gining, that the food is subjected in the stomach to an action similar 

 to that of the pestle and mortar of the apothecary, or of the millstone; 

 and that the chyle is formed like an emulsion. The most plausible 

 arguments, in favour of this view of the subject, are drawn from the 

 presumed analogy of the granivorous bird, whose stomach is capable 

 of exerting an astonishing degree of pressure on substances submitted 

 to it. There is no analogy, however, between the human stomach, and 

 the gizzard of birds. The latter is a masticatory organ, and therefore 

 possessed of the surprising powers which we have elsewhere described ; 

 whilst mastication, in man, is accomplished by distinct organs. No 

 comparison can be instituted between the gentle oscillatory motion of 

 the stomach, and the forcible compression exerted by the digastric 

 muscle of the gizzard. The simple introduction of the finger through 



1 De Medicina, cura E. Milligan, edit. 2da, p. 5, Edinb., 1831. 



2 Anatomy of the Human Body, &c., 8th edit., p. 155, Lond., 1763. 



3 De Motu Animalium ; Addit. J. Bernouillii, M.D., Medit. Mathem. Muscul., Lugd. Bat., 

 1710. 



4 Traite de la Digestion, Paris, 1710. 5 Haller, Elem. Physiol., xix. 5. 

 6 Works, &c., Lond., 1715. ' Cels., loc. citat. 



