142 On Rain IVater. [FbS^ 



been proved by Mr. Ellis * arid others; but all have neglected to 

 prove what becomes of the carbonic acid so formed. It would 

 seem, from its being found in a thunder-shower, that electricity- 

 has some influence in its modification. 



With respect to the existence of lime in the atmosphere,f it 

 may l)e accounted for in two ways, (at least by hypotheses:) — 

 1st. By evaporation. 1 believe it is now generally understood that 

 about X of the surface of the earth in this country is composed of 

 lime ; now, may not this be carried up in its most minute particles, 

 combined with the vapour which is exhaled from the earth's surface, 

 as pure lime, as a sub-carbonate, or as a super-carbonate ? (most 

 probably the latter.) The condensation of the vapour to form 

 rain would also he. a condensation of the particles of lime, which 

 may be sufhcient to account for the phenomenon mentioned. 



According to one theory of evaporation, this is possible.! 



Or it may perhaps be formed in the atmosphere itself, if it be 

 allowed that the gases exist in their separate states there. 



It is well known that nitrogen and hydrogen form ammonia. If 

 either of these substances be examined separately, no metaloid can 

 be detected; but if analyzed in the state of ammonia, it can.§ 



The base of lime is a metal. {| and some of its properties al- 

 lialine ; therefore, may not it be formed by gaseous matter, aided 

 by the electric influence ? 



The present state of science affords us but few proofs of the 

 causes of many of the phenomena of nature; I have, however, ven- 

 tured the above suggestions, for the want of better. Electricity 

 seems to be tiie active operating agent, the grand modificator of 

 matter ; scarcely a change takes place but it is caused by its in- 

 fluence. 



I hope this subject will be pursued by persons who reside in 

 different parts of the liingdom, in order to ascertain whether the 

 effects herein stated were caused by local circumstances. Should 

 this not be the case, I shall, at some future time, offer remarks on 

 the effects which such substances must necessarily have on the 

 animal and vegetable economy. 



* Vide Inquiries, &c. 



T When 1 fir't detected the lime, I was inclined to think that it miffht be caused 

 by t'letincr particles being carried up from neii^hbouring lin.c-kilns, &c, by as;i- 

 tatednir; and, in coiiseq'.ience, made the next experiment with water caught 

 from the top sound-hole of tiie cathedral of this place, a height of 300 feet : whe- 

 ther this height would be sufficient to obviate sucli an effect must remain to be 

 proved hereafter. 



% Vide D.-iIton's Essay, IVIan. Memoirs, vol. S. 



S Davys Chem. Phil. p. 473. B "^'^^^ P- 315, 



