1858. ] 435 
November 22d.’ 
Mr. Orb, President, in the Chair. 
Letters were read— 
Hrom the Historical Society of Pennsylvania, dated Nov. 15, 1853 ; 
from the Royal Geographical Institute of Vienna, dated August 21, 
1853 ; and from the Roya) Academy of Sciences of Stockholm, dated 
July 7, 1853, severally acknowledging the receipt of the Proceedings. 
From the Royal Geological Institute of Vienna, dated August 21, 
1353 ; from the Imperial Academy of Sciences of Vienna, dated August 
24,1853, and from Dr. M. Boué, addressed to Mr. Isaae Lea, severally 
accompanying donations to the Library announced this evening. 
Dr. 8. Weir Mitchell read a paper entitled “‘ On the effect of some 
states of Respiration upon the Pulse ;” which was referred to Dr. Leidy, 
Dr. Hallowell and Dr. Ruschenberger. 
Mr. Lea remarked that, when recently in Paris, he had found the 
original specimen of Mulleria, described by Ferussac in 1823, and again 
described by D’Orbigny as Acosta, which identity Mr. Lea had pointed 
out in a paper read before the Academy in 1851, and published in Part 
2, Vol. 2, New Series of the Journal. The specimen alluded to pos- 
sessed the appended bivalve shell which belonged to D’Orbigny’s spe- 
cimen. 
Mr. Lea also stated that the Reptiles referred to by Dr. Manitell, as 
occurring in the Old Red Sandstone of the North of Scotland, were now 
believed to be of a much later date. 
November 29th. 
Vice-President BripGss in the Chair. 
The Committee on Mr. Girard’s paper—‘ Researches upon Nemer- 
teaus and Planarians ’’—reported in favor of publication in the Journal. 
The Committee on the following paper by Dr. Mitchell, reported in 
favor of publication. 
On the influence of some states of Respiration upon the Pulse. 
By 8. Weir Mircuerz, M. D. 
I desire to offer to the Academy an abstract of a paper upon the influence of 
some states of respiration on the pulse. As the original paper will shortly ap- 
pear at length in the American Journal of Medical Science, I shall be as brief as 
possible. 
Laborious respiration may be studied under four heads. 
1. The movement of inspiration, thorax in motion. 
2. Complete and full inspiration, thorax at rest. 
3. The movement of expiration, thorax moving. 
4. Complete expiration, thorax at rest. . 
The dynamical relations of the blood to the heart and lungs will vary in each 
of these cases. 
During inspiratory movement the lung is expanded, and, while air passes into 
its cells, the blood of the greater vessels and of the two hearts tends to enter its 
sponge-like tissue, under the influence of atmospheric pressure. A reverse pro- 
cess occurs in expiration, and some blood, as well as most of the air is driven out 
of the lung. 
