Dr. Buchanan on the Effects of tlu> TnJialation of Ether. 1!J7 



E and W are two glass vessels, the one containing a small quantity of 

 ether, and the other of water. They aro shaped somewhat like the letter 

 U, having one limb or tube very narrow and the other wide. They aro 

 placed with these tubes in opposite directions — the one internal and the 

 other externa], in reference to the person who is to inhale the ether. In 

 the vessel E, the narrow tube is external and open at the top, while the 

 wide or intornal tube is shut, and has an elastic pipe attached to it. In 

 \\\ again, it is the wide tubo which is external and open, while the 

 i. arrow or internal one is shut, and has the pipe attached to it. The two 

 ic pipes terminate together at the mouth-piece. The effect of this 

 arrangement is, that when the person begins to breathe, the air inhaled 

 into the lungs can only gain admittance through the vessel E containing 

 the ether, and the air expelled from the lungs can only make its escape 

 through the vessel W containing the water. A current of air is thus 

 kept uj) in the direction indicated by the arrows from E to W, and the 

 as it enters at E and passes through the ether, is mingled with 

 ethereal vapour, and carries it along to the lungs. The mechanism by 

 wimh this is effected is of the simplest kind. The liquid in the vessels 

 E and W stands at the same level in the tubes of each vessel, so long as 

 the pressure of the air upon it is equal from within and from without. 

 But no sooner does the person begin to breathe, than, by expanding his 

 chest, he rarefies the air within, and thus diminishes the pressure upon the 

 surface of the liquid in the internal tubes. The consequence is, that the 

 liquid being forced inward by the pressure of the air from without, rises 

 in the internal and is depressed in the external tubes. But owing to the 

 Bmal] diameter of the external tube of E, only a very trifling elevation of 

 the liquid in the broad internal tube can take place before the whole 

 liquid in the external tube is exhausted, and the air rushes in to restore the 

 equilibrium. On the other hand, no air can enter through the vessel W, 

 owing to the reversed position of the two tubes, the broad one being 

 external, and the narrow one internal. These mechanical conditions are 

 just reversed during expiration ; for when the chest contracts, the air 

 within is condensed and acquires a greater tension, so that the liquid in 

 the two vessels E and W is now pressed more powerfully from within than 

 from without. It therefore rises in the external tubes, and is depressed 

 in the internal, till the whole liquid in the narrow internal tube of W 

 being exhausted, the air rushes out in that direction, and the equilibrium 

 is restored. 



Mr. Young of this city* suggested to me an improvement on the 

 apparatus just described, — that of putting the small tubes in the inside 

 of the large ones, — and had the kindness to construct for me an apparatus 

 of the kind. On trying it at the Infirmary, it was found to answer per- 

 fectly so long as the patient breathed calmly; but when he coughed, the 



* Mod reddtnl In Manchester, formerly assistant to Professor Graham, ami we$l 

 known for fail Ingenuity In tho construction of chemical apparatus. 



