S*ATE OF VAPOUR SUBSISTING IN THE ATMOSPHERJ. 213 



Note. — 1. Hence we fee that 1000 inches or meafures of 

 dry air at 32° would become 1004,4675 at 34,25 Fahr. and 

 at 50°. would become 1017,87. Hence 1000 meifures of 

 dry air gain 1,985555, &c. by each degree of Fahr. above 32° 

 (or morecompendiouily 1,9856 which is true to two decimal 

 places) or nearly two. 



2, We fee the fource of the difcordani refults of D'Amon- 

 toms, De Luc, Lambert, Schuckburg, Roy, Berthollet, and 

 Monge, &c. for they all operated upon air more impregnat- 

 ed with various degrees of moifture; beiides taking the boil- 

 ing point at different barometrical heights ; in the prefent ex- 

 periments it was taken at 29,841 Englifli inches. 



3. It appears that the expanfions are as the differences of 

 heat above 32° as D'Amontons, Lambert, and Schuckburg alfo 

 noticed, though their experiments, not being. made on perfectly 

 dry air, could not be very exact. 



The dilatation of the moifture contained in air has been fe- Dilatations of ait 

 parately examined by Mr. Schmidt, ami he has fhewn how from fat ^at«i with 

 it the volume of air iaturated with moiluire, laturated I fay at 

 every degree of Reaumur, may be difcovered ; the refult of 

 his experiments appear in the following table of the volume 

 which 1000 meafures at 32° of air would acquire if Jhturated 

 •with moijlure at each degree of Reaumur above 32° expreffed 

 on Farenheit's (bale *. 



