APPARENT PRODUCTION OF WATER. 27 



having mounted, cried " Here it is." The hard -wood had decayed, 

 leaving a very deep hole, which was almost closed at the top, 

 apparently by the spreading arch of subsequently formed bark. One 

 of the companions of the man cutting then a twig or shoot from the 

 root, cut through the bark of this at two places two feet or thirty 

 inches apart, treated this as boys in Europe treat branches of alder, 

 of which they wish to make whistles, beating and pressing it ; and 

 drawing out the wood, like drawing a sword fi'om its sheath, he 

 handed up the bark to the man aloft, who, using this as a suction- 

 pipe, soon quenched his thirst, and made way for the others iu 

 succession to do the same. 



Frequently did Mr Chapman while travelling avail himself of the 

 supply of water thus retained. 



Between the Victoria Falls of the Zambesi and Daka these trees 

 are found in clusters, sometimes 10 feet in circumference, and of 

 a much greater height than the other trees of the forest-country 

 around. They generally grow in clumps, in the higher portions of 

 the country. 



Similar supplies of water are found in the Pitcher Plant, and several 

 other herbaceous plants of somewhat similar structure ; and in the 

 Teazel, the Dipsacus fullonum, a quantity of water is often found in 

 the cup-like receptacle formed by the opposite leaves embracing 

 the stem. 



In more than one of these cases the water may possibly be only 

 rain-water collected and retained, and in the other cases it may be 

 elaborated sap, the water of which was derived from the soil ; but 

 even were such cases thus disposed of, the question has been raised 

 and awaits' an answer — May not water be a secretion of plants 

 themselves ? 



I have intimated or stated explicitly what are my views in regard 

 to the source of the great bulk of the moisture passed into the atmos- 

 phere by the stomates in the leaves of vegetable production ; but I 

 know of nothing incompatible with the supposition of a portion being 

 added from the combination of oxygen and hydrogen, meetino- in a 

 nascent condition in the process of chemical changes accompanying 

 vegetation. 



Water is a product of the combustion of wood, and of coal, of oil 

 of tallow, and of gas ; it is a product of respiration in man and many 

 other animals, and may be obtained deposited by their breath ; and 

 there are lower forms of animals by which it is produced, and that 



