ACTION OF CHLOROFORM UPON THE HEART AND ARTERIES. 317 
Another Heart : 
Amount flowing through coronary system before chloroform. : ‘ : : 45 ¢.c. 
*, * fs a fe during 5 (1 in 4000) . : ? 321s 
” ” ” ” bP] after 9 n ¥ ‘ . bs 42 ” 
Heart of Rabbit : 
Amount flowing through coronary system before chloroform. : : : ' 58 c.c. 
5 3p 93 5 » during - (1in 1500) . : 40 ,, 
5 of 3 7 ‘s after a : : : ; 48 ,, 
The same Heart, later : 
Amount flowing through coronary system before chloroform : : : : 48 c.¢. 
» » 2 5 A) during = (1 in 1000) . : : By 
39 00 a 5 a after 3 : 5 : : . 42, 
The tracing shown in fig. 3 gives an illustration of the effect produced upon the heart by a still stronger 
chloroform solution, the rate of perfusion falling during the passage of the chloroform from 21 c¢.c. per minute 
to 5 ¢.c. per minute, and gradually recovering as the chloroform was washed away. It will be noticed that 
the recovery of the vessels appears before the contractions of the heart reappear. It can also be seen that 
the latency of the arterial contraction is longer than that of the heart paralysis which the chloroform produces. 
Fic. 3.—Effect of perfusing 20 c.c. of chloroform-Ringer (=1 in 500) through the coronary vessels of the rabbit. 
a, tracing of manometer connected with supply cannula; 0, register of flow from coronary veins: each interval 
represents 7 ¢.c. ; c, time in minutes ; d, signal marking period of injection into supply tube. 
Note the diminution in rate of flow, and subsequent commencing recovery although the heart remains in a condition of 
arrest. The rate of movement of the paper is too slow for the individual heart-beats to be seen on the manometer tracing. 
Hind Limbs of Rabbit : 
Amount flowing through limbs before chloroform —. : ; 86 c.c. 
i a 7 » during a (1 in 10,000) . : . ees 
= _ » after = 3 ‘ : : : : 2 84 ,, 
Hind Limb of Rablit : 
Amount flowing through limb before chloroform : : 44 c.c, 
Pe 5 cs 5, after passage of 10 ¢.c. of 1 in 2000 chloroform-Ringer 39) 5; 
- - by », in-subsequent period . : : ; 2 : ; 42 ,, 
These observations show that the kidney differs from the other organs investigated 
in the fact that the more dilute solutions of chloroform produce an increased flow 
through the kidney vessels, whereas in the other organs (heart, limbs) the effect of the 
drug is always in the direction of vasoconstriction. The difference is a remarkable one ; 
but without discussing it at greater length, we may point out that dilatation of the 
renal vessels is the normal response of the organ to all but a very few excitants, whereas 
the normal response of most vessels to an excitation is contraction, and it is possible 
therefore that the explanation is connected with this difference of “habit” of the 
kidney vessels as compared with the systemic vessels generally. 
