00 Dn. Buchanan on fA* Effects of the Inhalation of Ether. 



filled with pure ethereal vapour. But such an atmosphere could not be 

 respired without immediately causing asphyxia from want of oxygen. 

 Even at the temperature of 64° the proportion of air in the atmosphere 

 of the chamber is reduced to one half, whence we may infer that during 

 the inhalation of ether, the application of artificial heat is both unnecessary 

 and dangerous, for by increasing the tension of the ethereal vapour the 

 proportion of common air in the atmosphere of the chamber is proportion- 

 ally diminished, and the risk of asphyxia made greater accordingly. 



To determine the weight of the ethereal vapour we assume that the 

 relation of 1 to 2*583 between the specific gravity of atmospheric air and 

 that of ethereal vapour is constant whenever they are at the same tempera- 

 ture and subjected to the same pressure. Taking, therefore, the weight 

 of a cubic inch of atmospheric air, when the barometer is at 30 inches, 

 to be -310117 of a grain at 60° F. it becomes -307695 gr. at 64°, and 

 •289595 gr. at 96°, whence we deduce the weight of a cubic inch of 

 ethereal vapour at 64° to be -3^7388 gr., and at 96° to be -748023 gr. 



To find the weight of the vapour inhaled in five minutes, we assume 

 that 18 respirations are made in the minute, and that 15 cubic inches of 

 gaseous fluid are taken into the lungs at each inspiration. We thus find 

 by calculation, that if it were possible for any person to breathe, for 

 five minutes, an atmosphere of ethereal vapour at 96° F., he would inhale 

 1010 grains of the vapour, or 2 medicinal ounces + 50 grains; and that 

 at the temperature of 64° there would be inhaled, in the same time, 536 

 grains, or an ounce + 56 grains. 



It thus appears, that at the temperature at which ether is commonly 

 inhaled, if the air in the chamber of the inhaler were fully saturated with 

 ethereal vapour, an ounce of it would be introduced into the lungs in five 

 minutes ; but of that quantity at least three-fourths would be again thrown 

 out with the expired air, so that only two drachms would remain to be 

 absorbed. There is, however, a still further reduction to be made, for 

 during the inhalation, the atmosphere of the chamber is undergoing a 

 continual renovation, and as the external air rushes into it with far greater 

 rapidity than the ethereal vapour is generated, there is not time enough 

 for the latter to attain its maximum tension. The deficiency thus 

 occasioned may probably be estimated at about one-half. It must 

 obviously be the greater the smaller the chamber of the inhaler, and wo 

 may therefore infer that there is an advantage in employing an apparatus 

 of which the chamber is of large size. 



Taking, then, into account the whole of the circumstances above 

 mentioned, it appears to me probable, that by the inhalation of ether 

 during the space of five minutes, not more than a drachm of it is introduced 

 into the blood; and yet that quantity has been found to induce such 

 a state of narcotism, that the most severe operations in surgery occasion 

 no feeling of pain. Now it has been stated above, that a quantity of 

 ether, seven times greater, has been administered by introducing it into 

 the stomach. This dose, though largely diluted with water, excited a 



