516 Notices of Memoirs—British Association— 
using as the starting-point the instance that the phenols obtained 
when coal is destructively distilled are derived from that particular 
class of compounds grouped as ‘cellulosic’. As plant mechanisms 
had evolved many distinctive forms of cellulose compounds even by 
the time of the Carboniferous epoch, we think it is necessary to 
ascertain whether the various modifications of cellulose differ 
materially in the compounds they yield, and if so which part of the 
plant substance’ corresponds to any particular coal-derivative. An 
illustration may be useful here: Conspicuous in the construction of 
many coals are the small yellow bodies known to everyone as spores. 
Their walls are formed of a derivative of cellulose. Are they, or are 
they not, still in a condition to react distinctively to treatment by 
pyridine ? Those who have experience in the examination of coals 
will recognize the practical difficulties in the way of anstvering so 
apparently simple a question, for hitherto spores have not been 
recognizable in lump coal but in thin sections, while, on the other 
hand, thin sections are not suitable for extraction hy pyridine. 
Nevertheless the difficulties have been overcome, and in the insoluble 
residue of coal extracted by pyridine we have observed unaltered 
spores in large numbers. This proves that the particular modification 
of cellulose forming their walls is one of the ‘cellulosic’ derivatives 
insoluble in pyridine. Since some coals are largely composed of spores 
this fact is of some value, more particularly as spores have a most 
distinctive appearance and are generally recognizable in thin sections. 
The next stage in the work is the isolation from coal of a sufficient 
number of spores to make possible a chemical examination to ascertain 
what particular type of chemical compounds they yield on destructive 
distillation. Spores, though the most conspicuous, are by no means © 
the principal constituents of most coals ; wood, soft parenchyma, cork, 
chlorophyll-containing or green tissues of leaves, must all have been 
universally present in proportions varying from inch to inch in the 
mass of débris from which any humic coal was formed. Cuticles, 
morphologically very distinctive portions of plants, and at the same 
time largely formed of a specific chemical compound to which the name 
cutin has been given, are conspicuous in the coal substance. We 
have now isolated sufficient pure cuticles from coal to distil them 
separately. It will be our business to track down the substances in 
coal one by one and to isolate them in such a form as will render 
their chemical examination possible. To hunt this extremely elusive 
game the microscope is necessary, and ‘the chemist alone is unable to 
interpret what is to be seen on its field; the palzobotanist alone 
cannot probe into the chemical composition of even the plant- 
structures he best recognizes. Thisis obviously a case for co-operation. 
The practical aim of such work should be to devise methods whereby 
satisfactory evidence can be obtained as to the most economic use to 
which a given seam can be put, coal being regarded not only as a fuel 
but as the source of innumerable, and some perhaps unsuspected, 
materials of increasing importance in modern life. The ultimate aim 
of the research is a complete scientific knowledge of the chemical 
composition and mode of formation of coal. 
Dr. Hickling desired to support all that had been said by the 
