290 Proceedings of the Royal Society 
our knowledge of the circulation of the blood in the Amphibia; for 
though Meckel had previously discovered that the auricle in the 
Pipa or Surinam toad was divided into two chambers by a mem- 
branous septum, yet the German anatomist regarded this as an 
exception ; and in common with every other anatomist, from the 
time of Harvey downwards, considered that the batrachian heart 
had, as a rule, only a single auricle, by which it was distinguished 
from that of the true reptiles. Davy, however, by showing that 
the auricle is double in the frog and in the common toad, established 
this important structural feature as an essential character of the 
Amphibia. 
Dr Davy’s extensive pathological experience afforded him the 
materials for his work on “ Diseases of the Army.” His Life of his 
brother Sir Humphry proves his aptitude for critical biography; 
while his numerous papers on Natural History, Chemistry, and 
Physiology, show still further how free from speciality was his 
active and inquiring mind. 
It is his physiological researches, however, and more especially 
those on animal heat, which stand forth with greatest prominence 
in the long list of his scientific labours. His observations on 
temperature, which extend to almost every important group of the 
animal kingdom, and embrace animals in almost every possible 
condition, are among the most valuable with which this depart- 
ment of inquiry has been enriched, and will always continue to be 
referred to by the historian of physiological progress. Among the 
very earliest of his publications is a paper presented to the Royal 
Society in 1814, on the difference of temperature between arterial 
and venous blood, and his last — that now before you — is still on 
his favourite subject. 
Dr Davy’s place in the history of scientific discovery has none of 
the brilliancy of his brother’s, but it will always be known as that 
of the uncompromising advocate of truth — the patient, painstaking, 
conscientious, and successful observer. The discovery of facts — the 
elucidation of positive truth — was his mission ; he seldom indulged 
in speculation, and did not possess that genius for generalisation 
which shed such a lustre over the career of the great chemist. 
The later years of his life were spent in his retirement at 
Lesketh How, near Ambleside. When I saw him there last 
