various other gqjeous Fluids. tyx 



*' into air. It is true, that we have not been able in our laboratories * to accomplifli the 

 ** changing of water into evaporation. This arifes from our being ignorant of the fliare 

 *• which eledlricity and light have in this natural procefs. Neverthelefs, it appears pro- 

 " bable to me, that the ponderable parts of atmofpheric air, that is to fay, oxygen and 

 *' azote has no other fource than the water with which the furface of the globe is covered. 

 " The very fmall quantity of oxygenous gas which is exhaled by vegetables by means of 

 " the fun, is far from being able to repair the enormous confurhption of that principle 

 *' which daily takes place in our atmofphere in fo niany different ways. NoW, fuppofing, 

 " according to this theory, that loo grains of water are changed, by the unknown procefs 

 *' of nature, into loo grains of atmofpheric air, that is to fay, into a chemical mixture of 

 " oxygen and hydrogen, we can find, by a very fimple calculation, in what proportion 

 *' oxygen and hydrogen are combined to form the azote which we obfcrve in the atmof- 

 " phere. Let us not, however, forget that the nature of what we call azote is not always 

 " the fame, and that it varies confiderably in the proportions of its conftituent prin- 

 "ciplest* 



*' I (hall call water E, oxygen O, hydrogen H, the ponderable part of the atmofpheric 

 " air L, the ponderable part of azote gas S. 



" Then lOO E = 85 O + 15 H. 

 " But a cubic inch of atmofpherical air is compofed of | of a cubic inch of gas, 

 " and -I of a cubic inch of azote gas ; therefore 

 I L = i O + -I S. 

 •' One inch of atmofpherical air weighs o : 46 grains. 

 " One inch of oxygenous gas weighs 0.5 1 grains. 

 " One cubic inch of azote gas weighs 0.44 grains i confcquently 

 0.46 L = ""V O + I0.44 S. 

 1.84 L = 0.51 O + 1.32 S. 

 184 L = 510+ 132 S. 

 100 L = 27.8 O + 72.2 S. 

 •' Azote gas being a compound of oxygen and hydrogen. 

 S = ArO+;)Hifo that 

 100 L = (27.8 + 72.2 *) O + 2 )> H- 

 «' Now nature changes lOO grains of water into an hundred grains of atmofpherical 

 *' air; confequently 



loO E r: .100 L; whence 

 27.8 . + 72.2 X = 85, and 

 72.27 =151 



• Sfe, however, Prieftley, in Philof. Journal, IV. 193, and elfewhere.— N. 



•f This is a very important point upon which Mr. Mayer fixes our attention. It will be neceflary to 

 snake a great number of very exail experiments to determine the different degrees of the oxydation of hydio- 

 gen, and to diAinguilb the different ga&s corapreh«aded, till now, under the general name of a2ote gas. 



Then, 



