SECT. XXXVIII. i. OXYGEXATION OF BLOQD. jj| 



SECT. XXXVIII. 



pf THE OXYGENATION OF THE BLOOD !J* TH$ 

 LUNGS, AND IN THE PLACENTA. 



f. Blood abforbs oxygene from the air, whence phofpho- 

 ric acid changes its colour, gives out heat, and fomc 

 phlogiftic material, and' acquires an ether ial fpirit, 

 which is dijjipated in fbrous motion. II. The placen- 

 ta is a pulmonary organ like the gills of fjh. Oxy* 

 genation of the blood from air, Jrom water, by lungs* 

 by gills, by the placenta ; necejjity of this oxygena- 

 tion to quadrupeds, to fjh, to the fatus in utero. 

 Placenta/ vejfels infer ted into the arteries of the mo- 

 ther. Ufe of cotyledons in cows. Why quadrupeds 

 have not fanguiferous lochia. Oxygenation of the 

 thick in the egg, of feeds. III. The liquor amnii is 

 not excrementitious. It is nutritious. It is found in 

 the efophagus and Jtomach, and forms the meconium. 

 Monftrous births without heads. Q^eflion of Dr. 

 Harvey. 



I. FROM the recent difcoveries of many ingeni- 

 ous philofophers it appears, that during refpiration 

 the blood imbibes the vital part of the air, called 

 oxygene, through the membranes of the lungs ; and 

 that hence refpiration may be aptly compared to 

 a flow combuftion. As in combuftion the oxygene 

 of the atmofphere unites with fome phlogiftic or 

 inflammable body, and forms an acid (as in the 

 production of vitriolic acid from fulphur, or car- 

 bonic acid from charcoal^) giving out at the fame 

 time a quantity of. the matter of heat ; fo in refpi- 

 ration 



