Serres? 
ieee ks 
ELECTRICAL PHENOMENA AND METABOLISM OF ARUM SPADICES. 319 
lower temperature and exothermal at a higher temperature, then its 
graph may be represented as under :— 
% of Chemical change 
Temperature 
The ascending portion of the curve represents chemical combination 
as induced by heat, the descending point chemical dissociation or decom- 
position induced by excitation, both, of course, being partial; the 
maximum point being that of injury or of initial excitation, as the 
case may be. 
The graph corresponds to the more general diagram by which Dr. 
Waller has represented the effects of heat and excitation, viz. :— 
Heat <—_  -——> 
Excitation or injury —> <— 
Such chemical changes of the inogen, as represented in the graph, 
correspond to well-known chemical changes such as the formation or 
decomposition of hydrogen iodide from or into its constituent elements, 
or of hydrogen sulphide and hydrogen selenide (cf. Bodenstein ‘ Zeit. 
Phys. Chem.’ 1899, 29, 295, 315, 429). 
From this standpoint it is quite conceivable that the chemical (and 
electrical) effects of heat and of excitation respectively should take place 
in opposite directions. The observations given in the Report appear to 
indicate that this is actually the case. 
The Effect of Climate upon Health and Disease.—Fourth Report 
of the Committee, consisting of Sir LaupER Brunton (Chair- 
man), Mr. J. Barcrort and Lieut.-Colonel R. J. 8. Simpson 
(Secretaries), Colonel Sir D. Brucs, Dr. S. G. CampsExL, Sir 
Kenpat Franks, Professor J. G. McKernpricx, Sir A. 
MitcHetu, Dr. C. F. K. Murray, Dr. C. Porter, Dr. J. L. 
Topp, Professor G. Sims WoopHeap, Sir A. E. Wricut, and 
the Heads of the Schools of Tropical Medicine of Liverpool, 
London, and Edinburgh. 
Tae Committee have received a number of communications from 
many parts of the world bearing upon various subjects of investigation. 
No progress has been made with the co-ordination of the data becausa 
