542 
POPULAR SCIENCE REVIEW. 
of the lateral fasciculi of the thyro-arytenoi’d muscle. That this condition is 
the true one was proved by the production of falsetto notes by an artificial 
larynx which had been arranged in the manner indicated above .“-“Vide 
Comptes Rendus, April 11th. 
Influence of the Spinal Nerves over the Action of the Heart. Several 
interesting though cruel experiments have lately been carried out on 
dogs, by M. Schiff, with the object of determining the extent of this 
influence. The animal is placed upon its back and kept in that position, 
and then two long and sharp needles are taken by the operator and 
plunged into the body : one of them, is driven in beside the sternum till 
it reaches the point of the heart, without wounding it ; the other is forced 
into the diaphragm. These two needles by their separate vibrations 
indicate respectively the movements of the circulatory and respiratory 
organs. When, under these conditions, the experimenter irritates any of 
the sensitive nerves of the head, as the anterior auricular or suborbital 
nerves, the movements of the heart slacken, often to as few as four pul- 
sations in the minute. If now the operator ceases to irritate the sensitive 
nerves, the action of the heart commences again. M. Schiff details the 
results of no less than eight different experiments made in this way, and 
terminates his memoir with this conclusion : in the spinal nerves the 
roots which operate upon the heart and larynx are by no means the same, 
for their filaments arise from distinct portions of the medulla, those 
presiding over movement arising more posteriorly than the others. 
The influence of the medulla oblongata upon the heart is not due to fila- 
ments which spring from the bulb properly so called, but to those which, 
in the interior of the medullary substance, descend towards the Spinal 
marrow of the neck, and leave this centre with the cervical roots of the 
spinal nerves. 
Condition of the Blood in Inflammation. — M M . Estor and Saint-Pierre 
affirm that the red colour of an inflamed part is due to the following 
circumstances (1) That the venous blood of the part contains a larger 
quantity of colouring matter than usual ; (2) that it contains a greater 
proportion of oxygen than that of the healthy part, for whilst that of the 
latter is represented by 1, that of the former rises to 1*50, and even to. 
2*50 ; (3) that the venous blood, during inflammation, contains a greater 
quantity of carbonic acid ; and (4) an increase of red colour is alwa}'S 
consequent on an increase of oxygen. — Vide Comptes Rendus, April 4th. 
Expulsion of Carbonic Acid from the Blood.— In one of the late numbers 
of the Proceedings of the Academy of Sciences of Vienna, a most inter- 
esting communication from Dr. Ludwig appears. In this paper the author 
demonstrates, by reference to the results of numerous experiments, that 
the removal of the carbonic acid is not due to any action of the tissue 
of the lungs, but simply results from the action of the oxygen. 
When blood was agitated with oxygen it was found to have lost its 
carbonic acid, and to have become to all intents and purposes arterial 
blood. To determine whether the evolution of carbonic acid is effected 
directly by the oxygen, or only by the intervention of the blood-cor- 
puscles, the purest possible serum which, as is well known, contains 
much carbonic acid, was employed, and, for the sake of comparison, both 
unaltered serum and such as had been agitated with oxygen. In these experi- 
