RELATIONS. 153 



use into the glass. Let any one show me any difference 

 between these two cases, as to the point of contrivance. 

 That which is at present under our consideration, the " re- 

 lation" of the parts successively employed, is not more 

 clear in the last case, than in the first. The aptness of the 

 jaws and teeth to prepare the food for the stomach, is, at 

 least, as manifest, as that of the cider-mill to crush the 

 apples for the press. The concoction of the food in the 

 stomach is as necessary for its future use, as the fementa- 

 tion of the slum in the vat is to the perfection of the liquor. 

 The disposal of the aliment afterwards, the action and 

 change which it undergoes, the rout which it is made to 

 take, in order that, and until that, it arrive at its destina- 

 tion, is more complex indeed, and intricate ; but, in the 

 midst of complication and intricacy, as evident and certain, 

 as is the apparatus of cocks, pipes, tunnels, for transferring 

 the cider from one vessel to another, of barrels and bottles 

 for preserving it till fit for use, or of cups and glasses for 

 bringing it, when wanted, to the lip of the consumer. The 

 character of the machinery is in both cases this, that one 

 part answers to another part, and every part to the final re 

 suit. 



This parallel between the alimentary operation and some 

 of the processes of art, might be carried further into detail. 

 Spallanzani has remarked* a circumstantial resemblance 

 between the stomachs of gallinaceous fowls and the struc- 

 ture of corn-nulls. Whilst the two sides of the gizzard per- 

 form the oflice of the mill-stones, the craw or crop supplies 

 the place of the hopper. When our fowls are abundantly 

 supplied with meat they soon fill their craw ; but it does 

 not immediately pass thence into the gizzard. It always 

 enters in very small quantities, in proportion to the progress 

 of trituration ; in like manner as in a mill, a receiver is 

 fixed above the two large stones which serve for grinding 

 the corn ; which receiver, although the corn be put into it 

 by bushels, allows the grain to dribble only in small quan- 

 tities into the central hole in the upper mill-stone. 



But we have not done with the alimentary history. There 

 subsists a general relation between the external organs of 

 an animal by which it procures its food, and the internal 



* Diss. I. sect. liv. 



O 2 



