G. W. Hawes— Composition of the wood of Acrogens. 585 
Art. LVIl—Contributions F be the Sheffield Laboratory of Yale 
College. No. XXX.—On the Chemical ie = my of the 
wood of Acrogens ; by aun W. Hawezs 
Patio matter. It was from this class of plants that coal 
was mostly formed, and the analyses will therefore be of value 
in calculations as to the origin and formation of coal beds. Some 
of them have been used by Prof. Dana in the new edition of 
his Geology in illustration of this subject. With the exception 
of on stem of the Tree-fern, the plants were collected near New 
en. Average samples of the part above ground were made, 
Scieding the spores, and. including, in the case of Lycopodium 
complanatum, a due proportion of the trailing stem, and in the 
ae of the fern, Aspidium marginale, a portion of the woody 
rhizom 
The bontivcalions were made with chromate of lead as an oxi- 
dant, but for the sake of experiment, the Equisetum and the 
Lycopodiums were afterward age: with the mixture of potas- 
sium dichromate and kaolin, which has been proposed as a sub- 
stitute by Prof. S. W. Johnson. (See this Journal for May.) 
The following were the results obtained: analyses 9 to 12 
are of the tree fern, 9 and 10 of a complete section of the stem 
or trunk, and 11 and 12 of the exterior or “ cortical” part. 
Carbon. Hydrogen. Oxygen. Nitrogen. Ash. 
741° 639. 45865. «614 s 
“Hise, seer pclenrmresemne Gaya 8 Ae el 
B: Toopodinis complaint: 4568 «Sa ares INE Be me 
5. Hquisetum hyemale, 4196 601 391 112 1170 100 
%. Aspidium marginale, tae bee ass 308 AT 100 
so Cris ceyalionians, wontion, [ee ee ae en ee 
Sn EES ee aos S088 Lal On - 
ing as the composition of the hy Weak goin Sp hie sy he a 
ebsky of a 
