fkeir Proditclion, Snispens'ioii, and Desf ruction. 107 



Hence also arise some further reflections on the purpose nn-« 

 swercd bv clouds iu the ceconomy of nature. Since rain 

 mav be produced by, and continue to full from, the slightest 

 obscuration of the sky by the nimbus (that is, by itva sheets 

 iu diH'crcnt states), while the cumulus o'r cuniulo-stratus, 

 with the Miost dark and threatening aspect, shall pass over 

 without letting fall a drop, until their change of state com-* 

 niences ; it should seem that the latter are resen'oirs in 

 which the \\'ater is collected from a large space of atmo- 

 sphere for occasional and local irrigation in dry seasons, 

 and by means of which it is also ai'rested at times in its 

 descent in the midst of wet ones*. In which so evident 

 provision for the sustenance of all animal and \'egetable life, 

 as well as for the success of mankind in that pursuit so es- 

 sential to their welfare, in temperate climates, of cultivat-» 

 ing the earth, we may discover the wisdom and goodness 

 of the creator and preserver of all things f. 



The nimbus, altliough in itself one of the least beautitil 

 clouds, is yet now and then superbly decorated with its at- 

 tendant the rainbow ; which can only be seen in perfection 

 when backed by the widely extended uniform gloom of liiis 

 modification:!:. 



The relations of rain, and of periodical showers more 

 especially, with the varying teniperaiure, density, and eltx- 

 tricitvof the atmosphere, will probablv now obtain a fuller 

 investigation, and with a belter prospect of success, thaa 

 heretofore. 

 [To be continued; when Platfs of rlie different Modifications vviil 

 be given.] 



XIX- Rp^emvlies respncti/fg the Organization of Leaves. 

 Bij A. .Ira INK, Meynbdr of the Society of Physics and 

 Katiiral History of Geneva. 



[Continued from p. 15.] 



AlAViVG described the organization of the surface of 

 leaves such a« I ubserved it, I shall proceed to their in- 

 terior organization, omitting at |iresent the diflerA.'nt vessels 

 found there, and which will be described in ihe second pari 

 of this memoir. 



The autiiors who speak of the purcnchynic deficribe it in 

 SO many ditfercnt ways that it seems dithcult to forju a just 



•* Null:i dies ;i(Ieo est Atistralibus humjda iiimbis 

 Non inierniissis lu fiiiat imbcr .iquis. 

 f See on this subject Job, clnp. xixvii and xxwiii. 

 X Bi"!/!/ iNOv.NS ^riK:, sHjs Virgil) in eiiumtratin^ tlic prognostics of 

 ^0n(inu(.d r.iin. 



idea 



