07t Capillary Acl'ion. 2d5 



out the end into a tapering capillary bore, and, a little above 

 this, bend the lliouldcr back parallel to the tube. Then, 

 holdino- the tube perpendicular, fill it with cold water, and 

 break off by deo-rees the (lender ftem till the water begins 

 to ipirt up perhaps half an inch. Now plunge the lower 

 end of the tube, for the fpace of a minute or two, m boihng 

 water, and, on removinc it, the jet will appear to dart almolt 

 to the height of three feet, but will gradually fubfide as the 

 heated portion of water is expended. 



The fame experiment will fucceed, though in different pro- 

 portions, with alcohol and even mercury. Yet all thefe are 

 commonly deemed perfeft fluids; nor can we doubt that the 

 application of heat will in every cafe increale the tenuity of 

 the liquid fubftance, and heighten its degree of fluidity. It 

 water thus experiences fuch a change, the effed muft be pro- 

 portionally jrreater on the dilute folution of mucilaginous and 

 faccharine matter which conftitutes the fap of plants. The 

 return of fpring, by the mere phyfical influence of its warnath, 

 will promote the flow of the juices dcftined for the nouriih- 

 ment of the vegetable tribes. That genial feafon, therefore, 

 not only reanimates the principle of life, and ftimulates the 

 organs of fecretion to elaborate their fluids, but quickens the 

 circulation of thofe fluids through the fine ramitications of 

 the fap-veflels. Hence the rapid" growth of plants in the hot 

 climates. Hence, likcwiie, the quick vegetation remarked 

 within the polar circle, where, ior the fpace of weeks or 

 months, the flanting rays of the fun play without intermifiion. 



Vcrf lilies, 

 Oittobtr 9, 1S02." 



• This ^-^per was drawn up in great hafte for a particular occafion. It 

 it nw/ printed without alteration, although tiic author is confcious of its 

 iivii£i.% in point of uaity and ari-angement. 



XXXI. Ob- 



