[ 207 jg^ 



fatient drink plentifully of liquors ftrongly impreg-- 

 nated with it. The event was fuch, that 1 requefted 

 Mr. Hey, to draw up a particular account of the cafe, 

 defcribing the whole of the treatment? that the pub- 

 lic might be fatisfied that this new application of 

 fixed air is perfectly fafe, and alfo have an oppor- 

 tunity of judging how far it had the effecl: which I \ 

 expected from it; and as the- application is new, 

 and not unpromifing, I (hall beg leave to fubjoin his 

 letter to me on the fuhject, by way of Appendix to 

 thefe papers, 



©f. Air in which a mixture of brimstone 

 and filings of iron has- stood, 



Finding in Dr. Hales's account of his experiments, 

 that there was a great diminution of the quantity of 

 air in which a mixture of powdered brimftone and 

 filings of iron, made into apafte with water,had ftood, 

 I repeated the experiment, and found the diminution 

 greater than I had expected. The diminution of 

 air by this procefs is made as effectually, and as ex* 

 peditioufly, in. quiekfilver as in water; and it may 

 be meafured with the greater!: accuracy, becaufe there 

 is neither any previous expansion nor increafe of the 

 quantity of air, and becaufe it is fome time before 

 it begins to have* any fenfible effecl:. The dimi- 

 nution of air by this procefs is, various; but I have 



generally 



