Dr. Meyen’s Researches in Physiological Botany. 141 
gioles” do not exist. All the analyses show that one may as- 
sume the proportion of oxygen to hydrogen to be as in water, 
and that these substances are isomeric (perhaps polymeric, 
H. C.) with starch, for the small differences found may be 
considered as faults in the analyses. With regard to these 
analyses it may be remarked, that however correct they may 
be, they by no means show us the correct composition of the 
primitive membrane ; for in the cells of the youngest ova, as 
well as in those of the cucumber, elder pith, and principally 
of the root-extremities, indeed, even in the fibres of cotton, 
there is contained a great quantity of organic substances 
which cannot be separated without destroying the tender tis- 
sue, and the presence of these matters renders the analyses of 
the membrane unsatisfactory. However, we may assume, that 
by far the greater portion of these substances have an isomeric 
constitution with starch. Moreover several kinds of wood 
were analysed in order to show the difference of composition 
of the primitive membranes of their cells. 
Oak. Box. Aspen. 
“An ”. “. 
£ ware Sie Be ae PO ~ 
Tn its na- Treated with Natural Treated with Treatedonce Treated twice 
tural state. carb. of soda. state. carb. soda. withcarb.sod. withcarb. sod. 
C ... 54°44 ...... BOGS ccécds DABS iiivecic 49°40 ...... 48°00 ...00. 47°71 
eS >t SE Un. scceks OSD sveeus GHD. ci a0s: 6°40 ...000 6°42 
OP fay OS cocece 44°30 ...000 BOSD ccnse 44°47 ...00. 45°06: scvcca 45°87 
From these analyses it certainly appears that in the ligneous 
substance, besides carbon and water, moreover free hydrogen 
must be present ; but here it must also be remarked, that it is 
almost impossible to separate the membrane of the woody 
cells from their contents, and the microscope shows that va- 
rious and perhaps resinous substances are contained in them. 
In a note sent into the Academy on the 24th of December, 
1838, M. Payen states, that by means of nitric acid he has ex- 
tracted the incrusting matter of the ligneous cells from the 
primitive membranes : for this purpose finely rasped oak and 
box wood were used. ‘The incrusting substance (by which is 
meant the inner layers of the cellular membrane) dissolved in 
nitric acid, and was thus separated from the residual tissue, 
which, after repeated purification, was dried and analysed. 
The composition was found to be 
Sh eae ts eo Se ee 
Rein! sass 6° ae OO 
RP sie 3 Se erin poe 
whilst the above analyses gave quite a different result. Ac- 
cording to this then the secondary layers of the cellular mem- 
brane must exhibit a striking difference in constitution ; but 
