212 STATE OF VAPOUR SUBSISTING IN THE ATMOSPHERE. 



Note. — lft. Moft of the interpolations from the 88th degree 

 to the 122nd I have myfelf inferted as thofe calculated by- 

 Schmidt erred too widely by his own account. 4Gren. Phyf. 

 Journ. 273. 



2d. Mr. Piclet has alfo made a fet of curious experiments 

 on the elafticity of pure vapour in low temperature. Ejfaisdc 

 jR/ty/tijue, p. 157. He found (hat a grain of warm water in 

 •vacuo evaporates in forty minutes in the temperature of 38^ 

 Fahr. under a receiver containing 1452 Englifli cubic inches,* 

 but that it did not diffufe itfelf equally in lefs than fix hours, 

 and then raifed the hygrometer from 17° to 60° that is 43°, 

 and during this whole time the cold under the receiver was 

 conftantly decreasing, though (lowly, which decreafe un- 

 doubtedly contributed to the diffufion of the vapour. 



Mr. Schmidt has alfo made aferies of experiments upon the 

 dilatibility of air, made as dry as, poffible by expofure to hot tar- 

 tctfin, an object of great importance, that had never before been 

 examined. This table I here infert, converting Reaumur's 

 degrees into thofe of Fahr. and adding from his formula the 

 degrees he omitted. 



' Expanfions of dry Air, 



* Ibid, page 91, 



Nits. 



