REMARKABLE EXPERIMENTS. 389 



independent than her Majesty's steam-ships, with their 

 apparatus for condensing steam, for, without coal, their 

 abundant supplies of sea-water are of no avail. I tried 

 the following experiment : — Finding a colony of these 

 insects busily distilling on a branch of the Ricinus com- 

 munis, or castor-oil plant, I denuded about 20 inches 

 of the bark on the tree side of the insects, and scraped 

 away the inner bark, so as to destroy all the ascending 

 vessels. I also cut a hole in the side of the branch, reach- 

 ing to the middle, and then cut out the pith and internal 

 vessels. The distillation was then going on at the rate 

 of one drop each 67 seconds, or about 2 ounces 5^ drams 

 in 24 hours. Next morning the distillation, so far from 

 being affected by the attempt to stop the supplies, sup- 

 posing they had come up through the branch from the 

 tree, was increased to a <±rop every 5 seconds, or 1 2 drops 

 per minute, making 1 pint (16 ounces) in every 24 hours. 

 I then cut the branch so much, that during the day it 

 broke ; but they still went on at the rate of a drop every 

 5 seconds, while another colony on a branch of the same 

 tree gave a drop every 17 seconds only, or at the rate of 

 about 10 ounces 4f drams in 24 hours. I finally cut off 

 the branch ; but this was too much for their patience, 

 for they immediately decamped, as insects will do from 

 either a dead branch or a dead animal, which Indian 

 hunters soon know, when they sit down on a recently 

 killed bear. The presence of greater moisture in the air 

 increased the power of these distillers : the period of 

 greatest activity was in the morning, when the air and 

 everything else was charged with dew. 



Having but one day left for experiment, I found again 

 that another colony on a branch, denuded in the same 

 way, yielded a drop every 2 seconds, or 4 pints 10 ounces 

 in 24 hours, while a colony on a branch untouched, yielded 

 a drop every 11 seconds, or 16 ounces 2|f drams in 24 

 hours. I regretted somewhat the want of time to institute 

 another experiment, namely, to cut a branch and place 

 it in water, so as to keep it in life, and then observe if there 

 was any diminution of the quantity of water in the vessel. 

 This alone was wanting to make it certain that they draw 

 water from the atmosphere. I imagine that they have 

 some power of which we are not aware, besides that nervous 

 influence which causes constant motion to our own in- 

 voluntary muscles, the power of life-long action without 



