104 



body, as they do in our lungs only. And hereby in 

 every inspiration the whole body is dilated, and in 

 every expiration compressed. 



But may it wot be doubted whether the primary end 

 of respiration be not to supply the whole animal ma^ 

 chine with the ethereal fire, a particle of which is con- 

 nected with every particle of air? Js not this detached 

 from it by the action of the lungs, and thence commu- 

 nicated to every part of the body ? And is not this the 

 true vital flame, the original source of life and motion. 



4. Chylification is preceded by digestion, which is 

 much illustrated by Mr. Papin's Digester. This is a 

 vessel wherein meat is put, with just as much water as 

 will fill it ; then the lid is screwed on so close as to ad- 

 mit of no external air. The meat herein is by the flame 

 of a small lamp, in six or eight minutes, brought to a 

 perfect pulp. In a few minutes mo're the hardest bones 

 are reduced to a jelly. No air entering, the succes- 

 sions caused by the air, enclosed in the flesh, resolve 

 the wfiole into one homogeneous body : it is just so in 

 digestion. In proportion to its heat the stomach does 

 the very same thing as the digester. 



Add to this, that the muscular coat of the stomach 

 continually contracting and pressing its contents by its 

 peristaltic motion, occasions a more intimate mixture, 

 and works the more fluid parts through the pylorus 

 into the duodenum. Along the sides of this and the 

 other small intestines the lac teals are planted: into the 

 minute orifices whereof the chyle or finer part of the 

 mass is received. The lacteal veins of the first kind 

 discharge themselves into the glands of the basis of the 

 mesentery. The chyle is afterward received by the 

 lacteals of the second kind, and conveyed into glands 

 between the two tendons of the diaphragm, and hence 

 it is carried to the heart, where it mixes with the blood. 



4 5. By the perpetual motion of the fluids, (especial. 

 }y in the minute vessels) as well as the constant 

 cation of the muscles, small particles are continually 



