"jo^r\l\jS^^^ on the Blood Corpuscles. 355 
the students of the Philadelphia Dental College the absorption of 
fats by the lacteals of the villi of the intestines, below the duct of 
the pancreas, and also the action of the heart and lungs ; neces- 
sitating as this did opening into the abdomen and thorax, life of 
course became extinct. 
When under the prolonged influence of nitrous oxide referred 
to, one of the blood-vessels of this animal was opened for the 
purpose of examining the blood corpuscles under the microscope, 
and ascertaining whether they had become disintegrated or any 
change had taken place in their form. On examination no per- 
ceptible difference was observable even after this lengthened ex- 
posure to the anaesthetic, when compared with the blood of another 
rabbit, which was not under its influence. This result induced me 
to examine into the statements made by Dr. Sansom, relative to 
the action of anaesthetics on the blood corpuscles in his highly 
interesting and able work on chloroform.* 
Prior to giving a description of my experiments in this direction, 
it may be proper to briefly refer to the prevalent theories on the 
physiological action of anaesthetics, also to the experiments per- 
formed and conclusions arrived at by Dr. Sansom. The view 
generally entertamed is that first suggested by Flourens, that these 
agents act directly upon the nerve centres, producing regular and 
progressive modifications in the functions of the brain and spinal 
axis, first affecting the cerebral hemisphere, then the power of co- 
ordination in the cerebellum, then the conduction of sensation and 
motion in the spinal cord, and lastly, if the agent is pushed so 
far as to decidedly impress the medulla oblongata, suspension of 
respiration and circulation. 
Dr. John Snow, regarding this theory as an erroneous one, and 
recognizing ether, chloroform, and other anaesthetics, as non- 
supporters of combustion, advanced the theory that these agents 
interfering with the introduction of oxygen into the system, induced 
their effect by the suspension of oxygenation, he therefore asserted 
that " narcotism is suspended oxygenation." This view is embraced 
and strongly advocated by Dr. B. Ward Kichardson (the friend, 
biographer, and editor of his work on ' Chloroform and other 
Anaesthetics '), and in England, apparently, is being very generally 
adopted by writers on this subject ; Dr. Kidd, who has devoted 
much attention to the study of the action of cliloroform, is, how- 
ever, a prominent exception. 
Dr. Sansom, accepting this theory, and knowing that nitrous 
oxide is not only an anaesthetic but a supporter of combustion, 
recognized the necessity of presenting something more conclusive 
in the support of the view, than had heretofore been offered. He 
* ' Chloroform, its Actions and Administrations.' By Arthur Ernest Sansom, 
M.B., London. Lindieay & Blakiston, Pliiladelphia. 
