289 
CHAPTER 1. 
OF THE CHEMICAL CONSTITUTION OF THE ELEMENTARY 
ORGANS. 
The tissue of plants, as it is first generated, and before it is 
incrusted with the peculiar secretions formed by the leaves, 
consists exclusively of oxygen, hydrogen, and carbon : and it 
is probable that none of the kinds of tissue differ originally in 
their proportions of these three principles ; for the microscope 
does not show a difference in the action of chemical agents 
upon them. 
I mention this because Mr. Rigg has arrived at a different 
conclusion, the accuracy of which has been insisted upon by 
the Rev. J. B. Reade, in a paper printed in Taylor's Maga- 
zine (Nov. 1837). It must be, however, apparent to any 
person conversant with vegetable anatomy, that such a separ- 
ation of tissue as in this case is supposed to have been ob- 
tained is physically impossible, and, consequently, the results 
given are fallacious. 
The subject has been subsequently taken up by Schleiden 
and Payen, whose experiments, made independently of each 
other, and in entirely different ways, both lead to the conclu- 
sion that the original tissue of plants is in all cases of the 
same chemical constitution, or nearly so, but that the sedi- 
mentary deposit which is formed inside each sac of tissue is 
of some other chemical nature ; the lignine of chemists is 
therefore composed of two or more different substances, viz. 
the primitive tissue and its subsequent incrustations. As this 
subject is important with reference to many phenomena in 
vegetable physiology, I give at some length the results of 
both Schleiden and Payen. 
The former makes a statement in Wiegman's Archives to 
the following effect : — 
‘‘ In the manuals which treat of organic chemistry, we 
generally find woody fibre treated of as a proximate element 
u 
