ON CHLOROFORM. 
99 
measure, yet the patient was ready for the operation to be- 
gin in less than a minute, and it was performed without 
the least sign of pain, being equal to the best cases of 
etherization. The patient recovered her consciousness, as 
might have been expected from narcotism by ether to the 
same degree, and she was going on well. Only one fluid 
drachm of the material was used, although about ten fluid 
drachms of ether v/ould probably have been used in the 
same operation. He (Dr. Snow) had inhaled it until he 
became miconscious, and was very sick afterwards, as on 
the only occasion on which he inhaled ether to the same 
extent. When the full effects of ether could be induced 
quickly, there was no preliminary excitement, and as the 
new agent produced its effects very speedily, excitement 
previous to insensibility could probably be altogether 
avoided in its use. The chloroform placed on the table 
had been given to him by Mr. Bullock, (he chemist; it had 
been rectified from chloride of calcium ; he (Dr. Snow) 
found its boiling point to be 140° ; he was not aware that 
the elastic force of its vapour, at other temperatures, had 
been ascertained ; but, from some experiments that he had 
made, it seemed to follow a ratio very similar to those for 
ether-vapour and vapour of water; he had ascertained the 
quantity of vapour of chloroform that air would hold in 
solution, at various temperatures, and it was shown in a 
table, of which the following is a copy. 
(Quantity that 100 cubic inches of air will take up. 
Temp. 
Cubic inches. 
50° 
- 9 
55° 
- 11 
60° 
- 14 
65° 
* 19 
70° 
^ 24 
75° 
- 29 
80° 
- 36 
S5° 
. 44 
90° 
- 55 
