) 



360 Mr. Henry on the Experiments made with 



rather drooping, and having been crufhed in 

 taking out of the machine, was thrown away. 



Two fprigs of mint, with feme loofe earth 

 adhering to their roots, were alfo kept in fimiJar 

 velTels, from the ift of September to the 12th 

 of the fame month, To the one a continued 

 current of fixed air was fupplied. The roots 

 of both were cut off on the 7th. The fprig in 

 common air exhibited fymptoms of decay on 

 the 1 2th day, but that in the ftream of fixed air 

 continued frefh above a week, after that in the 

 common air was decayed nearly to the top. The 

 experiment was then difcontinued, and the re- 

 maining plant foon withered. 



The next year I made the following experi- 

 ments, which farther confirm the truth of the 

 preceding ones which had been made both by 

 you and myfelf. In thefe, as alfo in thofe juft 

 related, the firft caufe of error was avoided, and 

 the proportion of fixed air was, in fome of them, 

 afcertained. 



1777, April nth, The weather being very 

 cold and vegetation backward — The middle 

 part of Nooth's machine was entirely filled with 

 fixed air, by firft filling it with water, inverting 

 it in the fame fluid, flopping up the capillary 

 tubes, and then driving out the water, from the 

 veflel, by fixed air from an efixfrvefcing mixture. 

 The middle, was the.i immediately placed on 

 the lower, part of the machine, containing ^n 

 cfFervefcing mixture alfo, which had been working 



