Further observations on the tolerance of gases by the circulatory apparatus

In the New York Medical Journal of November 26 and at the New Haven meeting of December, 1910, we gave observations on the quantities of gas (air) tolerated and the apparent relation of the adrenals to this tolerance. We have further determined that section of the cord between the fifth and sixth cervical vertebræ interferes with this tolerance of gas (air). After the removal of the adrenals from two dogs carbon dioxide was tolerated up to 942 c.c. in one case and 952 c.c. in the other, in 1 hour and 23 minutes.

Two dogs were injected with nitrogen. 1 One received 32 c.c. in six minutes with marked depressions; the animal lived. Panting occurred. The other received 272 c.c. within 22 minutes and died; panting was not noticed. The lungs were collapsed at autopsy.

The tolerance of oxygen was tested on two dogs. One received 150 c.c. slowly and survived. The other received 312 c.c. in 231/2 minutes and died. During the oxygen experiments, panting occurred. The lungs were practically normal.

The tolerance of hydrogen was tested in two dogs. In one 184 c.c. in 8 c.c. volumes were injected in 13½ minutes. Each injection caused a moderate depression. 60 c.c. were given in 20 c.c. volumes in 3½ minutes, and 20 c.c. in 5 c.c. volumes. The large volumes caused great depression and almost death. In the other dog 90 c.c. were injected in 7 minutes in 8 c.c. volumes without harmful results.

Sulphuretted hydrogen was used to study elimination on two dogs. Three C.C. saturated H₂S water were injected into the femoral vein. The breath almost immediately blackened lead acetate. Twenty-five minutes after tying and clamping off the adrenals 3 C.C. more of saturated H₂S water was injected and a similar result was obtained.