INTERNAL STRUCTURE OF PLANTS. 
11 
Schleiden has published an Appendix to this Treatise, in 
the same annual series of the Flora, p. 737. He is of opi- 
nion, that Mohl might have drawn two conclusions from his 
researches: — 1st, That iodine has no influence as a reagent 
upon starch, which indeed is the result of the discovery of 
the amyloid. Schleiden, together with Vogel, has found 
a substance in the cotyledonary cells of Schotia latifoUa, 
speciosa, Hymencea courhar, &c., which assumes a blue 
colour on the application of iodine, but in a different manner 
from starch ; and he has published this in Poggendorff’s 
Annals for 1839. 2dly, That the blue colouring of vegetable 
substances, by iodine, is no real chemical combination. Mohl 
has said, that the blue colouring of the membrane does not 
indicate a material difference from the ordinary membrane of 
the cell, on account of its not being probable, that cells formed 
of a different substance, should occur together in the same 
plant ; but with regard to this, the reporter replies, that the 
only point of importance, is the question of what is under- 
stood by the essential difference of two vegetable substances. 
Mohl seems inclined to leave this point to the chemists, but 
is however of opinion, that in that case we should have to 
wait some time. This is followed up by a remark, which 
deserves to be inserted here, as it marks the peculiar manner 
of Schleiden. “ On reading the good-for-nothing opinions of 
Berzelius and Liebig, respecting Schwann’s discoveries with 
regard to the (Gdhrungspilz) fungus of fermentation, one 
would suppose that these gentlemen had never heard of such 
a thing as a microscope. On hearing Berzelius speak of 
Schwann’s frivolousness, we do not know what to say to such 
absurdity. I should sincerely congratulate the science of 
chemistry, if Berzelius had always instituted his researches 
with a circumspection so thoroughly founded upon elaborate 
knowledge, and a profundity, combined with so much modest 
doubt in his own powers, as to secure him from the influence 
of preconceived opinions, as Schwann has done.* Did not 
* Schwann has written a book, called “ Microscopical Researches 
on the Identity of Structure and Growth of Animals and Plants” 
403 
