222 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
maximum about 24 hours after injury. This maximum was always 
between two and three times the ordinary plus temperature of the plant. 
In tubers (potatoes) the effect is local ; while in onion bulbs and other 
foliar tissues a much greater extent of tissue is affected. 
Action of Light on Diastase.* * * § — From a series of experiments on the 
action of light on various solutions containing diastase, Prof. J. B. 
Green comes to the conclusion that there exists in the leaf and in the 
various extracts examined, a certain amount of zymogen which is con- 
verted by the infra-red and the red, orange, and blue rays of the spec- 
trum into active diastase. The violet and ultra-violet rays, on the other 
hand, cause a destruction of the diastase, or at least such a change in 
the configuration of its molecule that it is unable to effect the hydro- 
lysis of starch. The enzyme is apparently not located in the chloro- 
phyll grain, but in the protoplasm of the cell. The author advocates 
the theory that the red colouring of certain leaves is a material help to 
the translocation of starch in them by screening off the rays which destroy 
the diastase. There appears also to exist in plants a power of absorbing 
and utilising the radiant energy of light, sometimes to a considerable 
extent, without the presence of a chlorophyll apparatus. 
Fermentative Power.f — Mr. A. J. Brown replies to Duclaux’s criti- 
cisms of the author’s views on Pasteur’s theory of fermentation. Mr. 
Brown had brought forward evidence to show that the argument on which 
Pasteur rested his theory was unsound, and that consequently that 
theory was untrustworthy. Pasteur had omitted to take time into con- 
sideration ; and as time enters into and governs the results from which the 
fermentative'power was calculated, the calculation was therefore erro- 
neous. The®author would abolish the expression fermentative power or 
S 
on the ground that it can never be applied to experimental work with 
S 
living organisms, and would retain fermentative activity, — , to express 
the fermentative pow r er of an organism in a unit of time. 
Alcoholic Fermentation without Yeast.f — It seems probable that 
Herr E. Buchner has obtained an alcoholic diastase capable of converting 
sugar into alcohol and carbonic acid without the intervention of yeast. 
Yeast is pounded up with infusorial earth to break down the cell-walls, 
and then submitted to hydraulic pressure. In this way is obtained what 
maybe called a solution of protoplasm, which, when mixed with a 20 to 40 
per cent, sugar solution, causes the evolution of gas bubbles in a few 
minutes, accompanied by the presence of alcohol in the liquid. 
Technical Mycology.§ — Herr F. Lafar has just brought out the first 
volume of his handbook on the physiology of fermentation. The work 
appeals to the chemist, brewer, farmer, and pharmacist. The first 
volume, with a preface by E. 0. Hansen, deals with Schizomycetes. 
* Proc. Roy. Soc., Ixi. (1897) pp. 25-8. 
t Central bl. Bakt. u. Par., 2 te Abt., iii. (1897) pp. 33-40. 
t Bor. Deutsch. Chem. Gesell., xxx. (1897) p. 117. See Aun. Inst. Pasteur, xi. 
(1897) p. 287. 
§ Jena, 1896. See Centralbl. Bakt. u. Par., 2 t0 Abt., iii. (1897) pp. 22-3. 
