0nd on ike Expansion of Moist Air. 427 



It may be recollected that Mr. Gough refers 

 us more than once for authority to the expe- 

 riments of Professor Schmidt of Giessen, which 

 have been largely quoted by Kirwan, in his 

 Essay on the Variations of the Atmosphere, in 

 the 8th vol. of the Irish Transactions. (See 

 also Nicholson's Journal, vol. 5, page 207). 

 This Gentleman made a scries of experiments 

 on the force of pure steam, and on tJic ex- 

 pansion of dry and moist air, which were pub- 

 lished in Gren's Physical Journal, 1798: Mr. 

 Kirwan's Essay was read in 1801, and in the 

 succeeding year ray essays on the same subjects 

 as Schniidt*s were published, without any ac- 

 quaintance with his results. — Mr. Kirwan, 

 finding Schmidt to be a careful experimenter 

 and well acquainted with the labours of his 

 |)rcdecessors, naturally gave him the preference 

 to them ; but not informing us of the structure 

 of his apparatus, we could gain no knowledge 

 on that head but from the original, a w^ork 

 scarce in this country. As the results of his 

 experiments on moist air, as cxhibiUd hij 

 Kirzvan^ differed remarkably from mine, I 

 was anxious to know the nature of his ap- 

 paratus : I wrote to him by a friend requesting 

 the favour of a plate or other descripticm of it ; 

 in the mean time, guided by the theory oi 

 moist air which I had confidence \v9;> fully 



