334 Proceedings of the Royal Society of Edinburgh. [Sess. 
negative. Later, some work was done by Hale-White (4) and Pembrey, who 
concluded that the action is due to increased tone of the muscles and 
increased muscular action. Ott (5) stated that tetra-hydro-/3-naphthylamine 
hydrochloride causes a rise of temperature after the animal has been freed 
from its stored glycogen, and he argues that the stimulation of the thermo- 
genic mechanism acts upon proteins to increase their combustion and to 
cause increased heat-production; but as his observations are not substantiated 
by determinations of the nitrogen excreted, his conclusions must be accepted 
with some reserve. 
The evidence upon which he supports his contention that the rise of 
temperature is not due to increased heat elimination through contraction of 
the peripheral vessels does not appear to be absolutely satisfactory. 
His early experiments to show that the drug no longer causes a rise of 
temperature after section below the tuber cinerium, and his later experi- 
ments to prove that it does not act if prevented by the injection of paraffin (5a) 
into the carotids from reaching his hypothetical thermogenic centres, do not 
fully dispose of the possibility of the rise of temperature being due to 
decreased heat-elimination. His further experiments on the effect of other 
vaso-constrictions upon the temperature are open to criticism, since the 
marked action of the drug upon the heart may have been sufficient to mask 
the effects of constriction of the arterioles upon the blood-pressure. 
A. Mode of Action of the Drug. 
The well-known action of such anaesthetics as ether and chloroform in 
causing a marked fall in temperature, with increased loss of heat from the 
skin, seemed to indicate that some light might be thrown upon the mode of 
action of tetra-hydro-/3-naphthylamine hydrochloride by its administration 
along with ether or chloroform, and, before proceeding to investigate its 
action on the metabolism, an investigation of this point was made. 
As a preliminary, (a) the normal variation in the rectal temperature of 
the rabbit was first investigated. Its limits were found to be between 
36-9° C. and 38-3° C. 
In these and in all my experiments the animal was not fixed down in 
any way. 
(b) On administering the drug the following results were obtained : — * 
(H)25 grm. steadied the temperature at 38'3° C* for two hours. 
0‘03 gave an almost similar result. 
0T0 gave a rise of temperature occurring in three-quarters of an hour, 
the maximum temperature of 39T° C. being reached in two and a half hours. 
* The injections were made by Dr E. P. Cathcart and by Professor Noel Paton. 
