104 SEVENTH REPORT—1 837. 
secrete siliceous or calcareous coverings, the author finding these pro- 
ducts to be capable of resisting the most intense heat, speculates on 
the importance of the facts he has established in explaining the forma- 
tion of the most characteristic rocks in the crust of the earth, and gives 
his reasons for believing that even in granite, as well as in flint (accord- 
ing to Ehrenberg), organization can be traced. A series of more than 
thirty microscopical illustrations accompanied the paper. 
On the Chemical Composition of Vegetable Membrane and Fibre. By 
the Rev. J. B. Reavez, W.A., F.RS. 
Specimens of Hrica Machaiana of Babington were exhibited by Mr. 
John Ball. 
MEDICAL SCIENCE. 
On the Influence of the Respiratory Organs on the Circulation of Blood 
in the Chest. By G. Catvert Hoiianp, M.D. 
There is little agreement, Dr. Holland observed, in the opinions of 
physiologists respecting the influence of respiration on the circulatory 
system. Some regard it as exceedingly limited, and the least efficient 
of the causes co-operating in the return of venous blood ; others con- 
tend that it is not only the principal but sole agent in the production of 
this effect. The author, from experiments on himself, stated that this 
influence is not great in the ordinary or unexcited conditions of the 
animal system, but peculiarly marked when the function of inspiration 
or expiration is unusually active or disturbed. Strong mental emo- 
tions, whether exciting or depressing, greatly disturb the respiratory 
functions, and, as a necessary consequence, the circulatory system. 
The author, in the continuation of his paper, examines respiration in 
its two acts, of inspiration and expiration, under various conditions ; 
and endeavours to prove that the phenomena of syncope and palpita- 
tion of the heart, referred by physiologists to the direct influence of the 
brain, arise from modification of the respiratory organs. 
On the Cause of Death from a Blow on the Stomach, with Remarks on 
the means best calculated to restore animation suspended by such ac- 
cident. By G. C. Hotranp, M.D. 
The occurrence of death from a blow on the stomach has not in mo- 
dern times received any full or satisfactory consideration. The cause 
of this phenomenon is usually referred to a shock communicated to 
