1Q0 PHILOSOPHICAL TRANSACTIONS. [ANNO 17Q8. 



half an hour; and that when they were taken out of it, all the 3 were alive. He 

 then allowed them to respire ahout half an hour, and again immersed them in the 

 warm milk, where they remained another half hour; and when taken out 2 were 

 vigorous, but the 3d seemed to languish: this submersion was again repeated, with- 

 out apparent injury to the animals. 



This experiment is so directly contrary to what we are led to believe from all 

 others, and also to the information derived from cases which frequently occur in 

 the practice of midwifery, in which an interruption to the circulation through the 

 umbilical chord occasions the death of the foetus, as to make me suspect its truth: 

 I was therefore induced to examine what would happen in a similar experiment. I 

 did not indeed cause the bitch to bring forth her puppies in water; but immersed a 

 puppy, shortly after its birth, under water which was of the animal temperature. 

 It lost all power of supporting itself in about 60 seconds^ and would shortly have 

 perished, had I not removed it into the air. Neither could I, by repeating this 

 experiment, so accustom the animal to the circulation of unoxygenated blood, as 

 to lengthen the term of its existence in such an unnatural situation. I thought 

 that a dog might have been made a good diver in this way; but having satisfied 

 myself that this could not be done, without greatly torturing the animal, I did not 

 choose to prosecute so cruel. an experiment. 



Young animals, indeed,, retain their irritability for a considerable time, so that 

 they move long after they have been plunged beneath water; and may even, on this 

 account, recover after they are taken out. But the manner in which Buffon has 

 related his experiment seems to imply; that the circulation of the blood, and other 

 functions of life, were continued after the animals had been excluded from the air. 

 I am convinced that the poor dog which was the subject of my experiment would 

 have been beyond recovery in a few minutes. Those animals which are accustomed 

 to remain long under water, probably first fill their lungs with air, which may, in 

 a partial manner, oxygenate their blood during their submersion. The true state- 

 ment of this subject may probably be, that the circulation of venous blood will de- 

 stroy most animals in a very short space of time; but that custom may enable others 

 to endure it, with very little change, for a longer period. 



VI. Analysis of the Earthy Substance from New South Wales, called Sydneia or 

 Terra Australis. By Charles Hatchett, Esq., F.R.S. p. 110. 



$ 1. The late ingenious Josiah Wedgwood, Esq., f.r.s., published, in the Phil. 

 Trans, for 1790, an account of some analytical experiments on a mineral substance 

 from Sydney Cove, in New South Wales. This substance he describes as com- 

 posed of a fine white sand, a soft white earth, some colourless micaceous particles, 

 and also some which were black, resembling black mica, or black lead. Nitric acid 

 did not appear to act on any part of this earthy substance ; and even a portion on 

 which sulphuric acid had been boiled to dryness, afforded afterwards, when edulco- 

 rated with water, only a few flocculi, which Mr. Wedgwood conceived to be alu- 



