480 PHILOSOPHICAL TRANSACTIONS. [aNNO i/SO. 



Dr. W. had tried the tinct. euphorb. cum camphord on a horse's leg several 

 times, and found it not near so caustic as without the camphor. And it is well 

 known how much camphor involves the spiculae, corrects the acrimony, and mi- 

 tigates the effects of can tha rides, saccharum Saturni, and rough, mercurial, and 

 antimonial preparations. Sthly, To water and oil therefore we may justly add 

 camphor as a powerful corrector and expeller of poisons in general. This it pro- 

 bably effectuates, 1st, by blunting the acrimony; 2dly, by calming the nervous 

 system, and securing it from spasmodic tumult and convulsion, which may be a 

 consequence of its sheathing quality ; 3dly, by its extreme subtilty and volatility, 

 by which it freely penetrates the smallest recesses of the body, and powerfully 

 promotes a diaphoresis. Some late instances of the effects of camphor in poison- 

 ous cases greatly confirm this account. 



These 3 simple bodies then, water, oil, and camphor, challenge the first place 

 among the antidotes hitherto discovered, both for internal and external use, and 

 are much more to be depended on than any of the elaborate compositions calcu- 

 lated for this purpose by the ancients, as the Theriac. Androm. Mithridat. Conf. 

 Paulin. &c. 



LXIV. Of Artificial Cold produced at Petersburg. By Dr. Hitwiel. Trans- 

 lated from the French by James Parsons, M, D., F. R. S. p. 67O. 



On Decem. 14, 1759, they had at Petersburg the most excessive cold weather 

 that ever was known, even to 205° of De Lisle's thermometer. At that time 

 Professor Braun repeated Fahrenheit's experiments in order to produce excessive 

 cold by means of spirit of nitre combined with snow. He saw with surprize the 

 quicksilver fall considerably in the thermometer, and descend even to 470^^ at 

 last; there the quicksilver remained fixed in the open air for the space of a quar- 

 ter of an hour, and did not begin to rise till it was carried into a warm room. 

 The immobility of the quicksilver made him conjecture that it might be frozen, 

 or become a solid body. But as Mr. Braun had not broken the glasses, he 

 could only at that time form a conjecture. Dec. 25 in the morning, between 9 

 and 10, De Lisle's thermometer was at the 199th degree of cold; and Mr. 

 Braun, as well as Professor ^pinus, then repealed this experiment. As soon as 

 the former had observed the quicksilver immoveable in the thermometer he 

 broke the glass; and he found the quicksilver frozen, but not entirely ; for in 

 the middle of the glass ball there was a small portion yet remaining fluid. Mr. 

 iEpinus's thermometer fell with extreme rapidity almost to the 500th degree, 

 and in breaking the glass from below, he found the quicksilver contained in it 

 absolutely frozen. Both these gentlemen found that the quicksilver, thus ren- 

 dered solid, bore hammering and extension, like other metals; but being after- 

 wards exposed to the open air, it soon recovered its former fluidity. Mr. ^Epinus 



