124 Correspondence of J. Nickles. 
To Mr. Payen this difference seemed only an apparent one; he be- 
lieved that in this latter case, the cellulose is incrusted with gum ‘and for- 
eign matters which hinder the solubility ; also the pith of the elder which 
is insoluble in Schweitzer’s reagent, becomes soluble in it when it has 
been previously treated with a weak acid such as dilute chlorohipirt sk 
Mr. Fremy supposed that the chlorohydric acid does not act as a solve 
of foreign matters, but that it converts one variety of cellulose into ro 
other variety, in the same way, for instance, as an acid converts cane 
sugar into glucose. 
We need not speak of the different phases of this discussion, for it is 
not yet settled. According to to Fre — we must admit at least two kinds 
into the same state s the most diverse reagents, such as mineral acids, 
organic acids, potassa, ammonia, etc. In order to prove that the differ- 
ences in the proper of cellulose are due to the state of the organi¢ 
substance f and not to the presence of mineral substances, Fremy 
as had recourse to the action of heat. In exposing vegetable pith, 
which is insoluble in the cupreous reagent, to the action of a tempera 
ture not exceeding 30°, and maintaining it at that point - —— i 
he has that substance become soluble in the above 
rived at an analogous result by keeping the cellular ine of pith fot 
twenty- four — in boiling water. 
e, he has remarked that this change takes place only in the 
organic sibetance of the tissue, for the proportion of mineral matter re 
ch 
mained the same in both cases, and the tissue which had become soluble 
in the cupreous sige ray after its calcination a mineral network, re 
producing exactly th e form of the vegetable cellules, which same thing 
ous reage 
directly without ge treatment. Cellulose is — in cotton, fibres 
same effect to a certain point, in forming a protective envelop ; ius rding 
i b 
then placed a deilenttnd mixture, After con congea ling, the . 
containing 15 per cent of m Faeetl substa . These a a su 
according to Powe prevent the complete a solution of the cellul 
