58 THE PHILOSOPHY 



milky particles. The thinner and more perfeclly digefted 

 parts of the food gradually pafs through the pyloricsy or lower 

 aperture of the ftomach, into the inteftines, where they are 

 ftill farther attenuated and digefted by the bile and pancrea- 

 tic juices. "While the food is in this fluid ftate, it receives 

 the denomination of chyle^ and is continually abforbed by the 

 mouths of the la£teal veins. Thefe veflels arife, like net- 

 work, from the inner fervice of the inteftines, pafs obliquely 

 through their coats, and^ running along the mefentery, unite, 

 as they advance, into larger branches, and at laft terminate 

 in the thoracic du6t, or general receptacle of the chyle. Be- 

 fide the ladleals, there is another fyftem of veiTels called 

 lymphatic^ or abforbent veins : They are minute pellucid 

 tubes, and generally lie clofe to the large blood-veffels. The 

 lymphatics from all the lower parts of the body gradually 

 unite as they approach the thoracic du61:, into which they 

 pour a colourlefs fluid by three or four large trunks j and 

 the lymphatics from all the fuperior parts of the body like- 

 wife difcharge their lymph into the fame du6l as it runs up- 

 ward to terminate in the left fubclavian vein. By this cu- 

 rious and beautiful machinery, the chyle and lymph, which 

 confift of the nutritious matters extracted from the food, 

 enter the circulating fyftem, are converted into blood, and 

 afford that conftant fupply of nourifhment which the per- 

 petual wafte of our bodies demands. 



We fhall next give a fketch of thofe important organs by 

 which we are enabled to multiply and continue the fpecies. 

 The circulation of the blood, and the mode by which the 

 quantity of it is continually kept up by frefti fupplies of 

 chyle, are efte(n:s which, in fome meafure, correfpond with 

 our ideas of the machinery employed. The organs of gener- 

 ation exhibit a ftill more complex fpecimen of exquifite 

 mechanifm. But the machinery employed, without the aid 

 of experience, could never fuggeft the moft diftant idea oi 

 >he efted to be produced. 



