THE USE OF ANAESTHETICS. 
17 
are desired, the second to moderate excessive labor pains, 
and the third where serious surgical operations are to be per¬ 
formed. This stage may be maintained with care for several 
hours. After complete unconsciousness takes place, if the in¬ 
halation is continued, the respiratory centre becomes para¬ 
lyzed, respiration ceases, the heart’s action loses force, and 
finally stops altogether. The dangers of anesthesia depend 
on an over-dose of the agent, or in some instances from sud¬ 
den collapse during the first few inhalations, (due, probably, 
to some organic change in the heart or lungs) and on suffoca¬ 
tion from blood or other matters getting into the trachea. 
There are a great many substances of so volatile a charac¬ 
ter that they can be employed in producing anesthesia, but of 
the many, there are but four that are in common use, viz.: 
alcohol, ether, chloroform and nitrous oxide, and in practice 
the first three are only used either alone or mixed in various 
proportions. Careful experiments have demonstrated that 
where combinations of chloroform, alcohol and ether are 
poured on an inhaler, the most volatile spirit will rise first, 
then the next, leaving the least-easily evaporated on the in¬ 
haler. This should always be considered and the same pre¬ 
cautions observed as in the use of either agent alone. Alcohol 
is only used in combination with ether and chloroform. 
With the medical profession, there has probably been in 
America more opposition to the use of chloroform in favor of 
ether than in any other country, but there seems to be a 
change lately in favor of chloroform, from the fact of so many 
fatalities occurring where patients were affected with kidney 
trouble, and this being the case with so many where there 
was not even a suspicion. This reason does not prevent its 
use in veterinary practice, but the difficulty of producing an¬ 
esthesia, which is also experienced in some instances by the 
most careful and competent human administrators who are 
finally compelled to resort to chloroform. Another reason is 
the danger of bronchial and pulmonary irritation following, 
which the horse is particularly susceptible to. It is danger¬ 
ous to administer the vapor in as concentrated a form as that 
of chloroform. These should not be administered to patients 
