B58 
Action of Ansesthetics 
[Month ly Microscopical . 
Journal, June 1, 1869. 
influence of ether, cliloroform, or nitrous oxide, for tlie extraction 
of teeth, has yielded similar results. 
The results of these investigations were recently presented to 
the members of the Microscopical and Biological Department of 
the Academy of Natural Sciences, illustrated by a large number of 
microscopical slides, and although some time has elapsed since the 
blood was placed on many of them, the corpuscles retain their form 
unchanged. 
Presenting the statements for what they are worth, and desir- 
ing that others may either confirm or disprove them by experiments 
of their own, as carefully conducted and as frequently repeated, and 
not merely performing a few experiments and then drawing con- 
clusions which they would not be warranted in doing, I would 
suggest to such that there are two modes of preparing blood for 
microscopical examination, each of which has been tried in my 
investigations. First plan — the blood, placed on a slide, is spread 
with a knife-blade thinly over the glass, then waving it backward 
and forward in the air, the blood is dried by evaporation, and can 
be covered with a thin glass slide, cemented, and kept for a con- 
siderable length of time without change. Second plan — a drop of 
blood is placed on the slide, a thin glass cover is brought in contact 
with the edge of the drop, and by capillary attraction, a stratum of 
blood is drawn under it. Although this answers for immediate 
examination, unless some menstruum is employed for the preserva- 
tion of the blood, its characteristics become so completely changed 
in the process of coagulation that the specimens become useless. 
In pursuing these investigations, care must be exercised to prevent 
the direct contact of ether and chloroform with the blood corpuscles, 
as this makes the greatest possible difference. 
In conclusion, although it is not my intention in this commu- 
nication to engage in an extended inquiry relative to how ansesthe- 
tics produce these effects, it seems to me that the above experiments 
demonstrate that we are not warranted in denying that these agents 
act directly upon the nerve centres. All the phenomena, indeed, 
attendant upon their administration, the gradual exaltation of the 
cerebral functions followed by the progressive impairment and tem- 
porary suspension of the special senses, the loss of co-ordination on 
the part of the cerebellum, and when the agent is pushed too far, 
the arrest of respiration and circulation through the decided impres- 
sion made upon the medulla oblongata, seem to favour this hypo- 
thesis, in contradistinction to the theory that anaesthesia is due to 
suspension of oxygenation. 
In connection with this, I cannot refrain from saying, when 
taking into consideration the readiness with which fluids absorb 
gases, that undue prominence apparently has been given by phy- 
siologists to the blood corpuscles as the carriers of oxygen to the 
