DISAPPEAaANCE OK OXIGEN AND HIDROGE>r. QQt 



and I confidently expe6l that many fa6ks, hitlierto rererred to 

 chemical principles, will be brought, in confequence of your 

 difcoverics, within the pale of mechanical philofophy.* 

 I am. Dear Sir, 



Your's very truly, 



WILLIAM HENRY. 

 Manchefter,June 20, ] 801-. 



XIIL 



On the D/fappearance of Oxigen and Hidrogen over Water, at 

 the Heat of the Atmofphere. By T. S. T, 



To Mr. NICHOLSON. 

 SIR, 



OOME months ago, I read in your excellent Journal an ac- SIdw abfr>rptioa 

 count of an experiment, which tended to ftiew that oxyge- J'f oxigtn and 



' r I ■ 1 hidrogen over 



nous and hydrogenous gafes, when mixed together, and al- water. 

 lowed to remain over the furface of water for a long time, 

 fpontaneoiifly united and formed water. 



Having long been accutiomed to confider a temperature 

 confiderably higher than that our atmofphere ever at{aiii<;, ne- 

 ceflary to this union, I was naturally led fo invefligate this 

 phenomenon ; and for that purpofe undertook the following 

 experiments : 



1. I prepared oxygen gas from black oxide of manganefe, 

 by means of concentrated fulphuric acid, aided by he-at, and 

 in order to render it more pure, I wallied it well with milk of 

 lime. I prepared likewife a quantity of hydrogen gas, by 

 paffing a. few drops of water through a gun-barrel, filled witli 

 iron filings, and pafled through the body of a fmall furnace, I 

 introduced nearly equal quantities for both gafes into a bell- 

 glafs jar, placed on the flielf of a common pneumatic trough, 

 which ftood in a room without fire, and alinofl without light. 

 The mixture was fuffered to remain in that fituation for about 

 five months; at the end of which lime, the volume of the 

 gafes had diminiflied J. 



* As the author had not feen Mr. Dalton's letter, publi.lied in our 

 laft number, at the time when thefe illuftrjtionswjrc written, he has 

 mentioned a few circumftances contained in the letter, 



2. On 



