ON ANAISTHETICS. 313 
anesthetics, with precise knowledge of the actual mass of the anesthetic 
introduced into the organism, The comparison of ether with chloroform 
introduced by inhalation is valuable and necessary, inasmuch as in- 
halation is the ordinary and regular means of introduction; but for an 
exact knowledge of the comparative effects of ether and chloroform at 
equal masses of the two drugs, inhalation is inadmissible, and it is 
necessary to proceed by intravenous injection. 
The solubility of ether in saline—upwards of 8 per cent. at ordinary 
temperature—permits the employment of a solution of ether in saline at 
5 per cent. by weight. 
We used, therefore, a 5 per cent. solution of ether in comparison with 
a 0°5 per cent. solution of chloroform, i.e., a mass relation of 10 grammes 
of ether to 1 gramme of chloroform (or a molecular relation of 16 mols. 
of ether to 1 mol. of chloroform). 
In experiment No. 2 we noted that the injections of 10 c.c. of 5 per 
cent. ‘ ether saline ’ produced rather larger effects on the blood-pressure 
than did an equal volume of 0°5 per cent. of chloroform saline; but in 
this experiment we had not insured that the intravenous injections of 
10 c.c. were made with equal rapidity, and we did not, as in our next 
experiment, systematically alternate the injections of chloroform and 
ether ; we also noted in this experiment that the ether injections produced 
a greater effect on the respiratory movements than the injections of 
chloroform. 
Eaperiment No. 2.—July 29,1909. Cat 35 hilos. 
Fall of 
Blood-pressure. Blood-pressure. 
Min. Mm. Hg. Mm. Hg. 
14 Eth, 145 25 
18 Chl, 160 15 
32 Eth, 150 50 
35 Chi, 155 35 
52 Eth, 160 120 
55 Ch], 135 25 
67* Eth, 155 70 
70* Chl,, 155 20 
90 Eth,, 150 100 
93 Chl,, 140 30 
98 Chl,, 145 25 
101 Eth,, 140 70 
Experiment No. 3.—July 30,1909. (Alternate injections of 10 c.c. of Chloroform 
Saline and Ether Saline.) 
Fall of 
Blood-pressure. Blood-pressure. 
Min. Mm. Hg. Mm. Hg. Resp. 
4 C, 140 80 Diminution 
8 E, 100 70 ; Arrest 
16 Cc, 160 70 Brief arrest 
23 E, 150 70 Arrest (art. resp.) 
27 C; 170 80 Arrest 
32 E, 160 100 Arrest 
41 C, 150 80 Brief arrest 
45 E, (8 c.c.) 150 80 to 110 Arrest 
4) C; 140 70 No effect 
53 E, (8 ¢.c.) 140 70 to 90 Arrest 
60t is 130 90 Arrest 
67+ E, (8 cc.) 140 70 to 90 Arrest 
74 C, 140 90 Arrest 
80 EK, (8 c.c.) 100 Death Permanent arrest; 
* See Plate XI, t See Plate XII, 
