212 THE AMERICAN MONTHLY [ November, 
Protoplasm. 
Sir H. E. Roscoe, in his address as president of the British Association, 
in a résumé of the history of,chemistry, remarked of protoplasm as follows :— 
‘ But now the question may well be put, Is any limit set to this synthetic power 
of the chemist? Although the danger of dogmatizing as to the progress of 
science has already been shown in too many instances, yet one cannot help 
feeling that the barrier which exists between the organized and unorganized 
worlds is one which the chemist at present sees no chance of breaking down. 
It is true that there are those who profess to foresee that the day will arrive 
when the chemist, by a succession of constructive efforts, may pass beyond 
albumen and gather the elements of lifeless matter into a living structure. 
Whatever may be said regarding this from other standpoints, the chemist 
can only say that at present no such problem lies within his province. Pro- 
toplasm, with which the simplest manifestations of life are associated, is not 
a compound, but a structure built up of compounds. The chemist may suc- 
cessfully synthesize any of its component molecules, but he has no more reason 
to look forward to the synthetic production of the structure than to imagine 
that the synthesis of gallic acid leads to the artificial production of gall-nuts. 
Although there is thus no prospect of our effecting a synthesis of organized 
material, yet the progress made in our knowledge of the chemistry of life 
during the last fifty years has been very great, and so much so, indeed, that 
the sciences of physiological and pathological chemistry may be said to have 
entirely arisen within this period.’ 
MICROSCOPICAL TECHNIQUE. 
A new paraffin imbedding apparatus.*—Those who have had much ex- 
perience in imbedding in paraffin are aware of the difficulties and risks which 
attend the imbedding of delicate objects on account of the danger of over- 
heating the imbedding mass. The trouble with heat regulators is that they 
get out of order and give trouble, aside from the difficulty which arises from 
the variations in the pressure of the gas in the pipes which supply the burn- 
ners, and which is entirely beyond the control of most forms of the ther- 
mostat. Asa substitute for them the following plan is suggested by Prof. 
Ryder in the American Naturalist :— 
A triangular sheet of copper, slightly less than ;4 in. thick, 18-in. long, 
and 10 in. wide at one end and running to a sharp point at the other, is sup- 
ported horizontally upon two legs at the wide end, and at some distance from 
the pointed end by another leg, these three legs constituting a firm tripod 
base for the whole device. Under the pointed end of the triangular plate of 
copper a flame is allowed to burn steadily and permitted to play upon the 
copper plate at a distance of about 1 in. from its extreme point; the whole 
plate will soon be heated, but the temperature will be found to gradually 
diminish towards the wide end. At a distance of about 12 to 13 in. from the 
point where the flame acts upon the copper plate the temperature will remain 
steadily at about 56° C. (133° F.), with the temperature of the room at 22° 
C., or 71° F. As long as the temperature of the room rematns nearly the 
same the temperature of the plate at any given distance from the burner will 
also remain at the same point. This constancy is due to the fact that the 
heat which is conducted through the copper plate with constant rapidity from 
* We have taken this account of Prof. Ryder’s excellent device, shortened and with minor omissions, from 
the Exglish Mechanic. It is especially valuable because of the readiness with which it can be used with an al- 
cohol lamp. It, however, would seem more subject to change in temperature in the room than the water-bath 
apparatus.—Ep. 
