J50 I-HILOSOPHICAL TKANSACTIONS. [aNNO 1743. 



the particles of fire ; by which action the particles of air will recover their elasti- 

 city, and, putting the particles of fire in motion, cause heat or warmth, but not 

 incension or inflagration ; unless the fire thus agitated meets with a proper pabu- 

 lum, which pabulum is sulphur only, though differently modified, whether under 

 the appearance of brimstone, bitumen, oil, vinous spirits, vegetable substances 

 when deprived of their water, metalline sulphurs, or the most inflammable of all, 

 animal sulphur, commonly called by modern chemists phosphorus. 



Thus in fermentation, the fire and air being let loose, produce a warmth, but 

 do not kindle, because of the water predominating ; whereas in the effervescence 

 produced by the solution of metals, the fire meets with the metalline sulphur, 

 which it kindles, and sometimes causes explosions; the aromatic oils containing 

 but little water, being almost entirely composed of the sulphureous parts of the 

 vegetables, immediately kindle, and break out into flame ; and phosphorus, 

 which is nothing but the animal sulphur, as appears by the curious account of it 

 given us by that late ingenious chemist Mr. Godfry, a worthy member of this 

 Society, (see Trans. N" 428,) is so greatly disposed to take fire, that if it be only 

 exposed a few minutes to the open air, it kindles and flames. 



Now all animals, on which experiments have been made, are found to contain 

 more or less of the phosphoreal principles ; some insects constantly shine, or emit 

 light in the open air ; many sorts of fish are luminous, if exposed to the air a 

 short time ; nay, even the bubbles of the sea water appear like fire in the dark : 

 some quadrupeds have been observed to emit light on very slight friction of their 

 hair, as the necks of horses, the backs of cats, and the like ; and there are many 

 instances in our own species, of many parts of the body appearing luminous, and 

 even of the exhalations from it adhering to the clothes, causing them to shine 

 likewise ; of which several curious observations have lately been laid before this 

 Society. These are convincing proofs of phosphorus existing, at least in a dor- 

 mant state, in animal fluids ; and as it is likewise certain that they all contain 

 air, it is only necessary to bring the phosphoreal and aerial particles to contact, 

 and heat must of consequence be generated ; and was it not for the superabun- 

 dance of aqueous humours in animals, doubtless fatal incensions would frequently 

 happen. This explains evidently the cause of animal heat : indeed the heart and 

 arteries are the instruments which excite this heat ; but that is not done by tht; 

 friction caused by the circulation of the humours, but only by the intestine mo- 

 tion, which the circulation gives to the several particles which constitute the mass 

 of animal fluids ; and as the velocity of these fluids is increased, so must the dif- 

 ferent particles, of which they consist, come oftner into contact ; and consequently 

 the phosphoreal and the aerial meet, the more frequent and greater must the 

 nisuses be to create heat. 



Hippocrates, Aph. 1, 14, mentions the Qi^fAov iji/.^utoi/, calidum innatum. 



