204 GEOLOGICAL SYSTEMS AND ENDEMIC DISEASES. 
treated with the carbonic acid under pressure and gentle 
warmth, 26° F., the colloidal part was separated ; but when 
the blood with the fibrine removed from it was treated there 
was no direct separation, the blood-corpuscles seeming for a 
time to engage the gas by condensation of it. But blood 
containing tibrine, and held fluid by tribasic phosphate of 
soda, was at once coagulated by the acid. The bronchial 
secretion was thickened by carbonic acid, and a tenacious 
fluid was obtained, resembling the secretion which occurred 
in asthma and bronchitis, while secretions on serous surfaces 
were thickened and rendered adhesive. After detailing many 
other facts. Dr. Richardson concluded by showing what 
bearing this subject had of a practical kind. In the first 
place, the research had relation to the question of elasticity of 
organic substance ; and secondly, on the direct action of car- 
bonic acid on the production of vegetable juices. But the 
greatest interest concentrated on the relation of the research 
to some of the diseases of the animal body. Thus, in in- 
stances where the temperature of the body was raised and the 
production of carbonic acid was excessive, the blood on the 
right side of the heart had its fibrine often precipitated, and 
in many other cases fibrinous or albuminous exuded fluids 
were solidified, as was the case in croup. The author, in the 
course of his paper, explained how rapidly blood charged 
with carbonic acid absorbed oxygen when exposed to that gas; 
and held that carbonic acid in the venous blood w r as as essen- 
tial to the process of respiration as was the oxygen in the 
pulmonary organs. 
GEOLOGICAL SYSTEMS AND ENDEMIC DISEASES. 
Some little time ago, Dr. Moffat read a paper showing 
that the soil has an influence on the composition of the 
cereal plants grown upon it, and on the diseases to which 
the inhabitants are subject. The district in which he prac- 
tises consists geologically of the carboniferous and new red 
sandstone, or Cheshire sandstone systems. The inhabitants 
of the first are engaged in mining and agricultural occupa- 
tions, those of the latter in agriculture. Anaemia, with 
goitre, is a very prevalent disease among those living on 
the carboniferous system, whilst it is almost unknown among 
those living on the new red sandstone system, and consump- 
tion is also more prevalent amongst the inhabitants of the 
former. 
