650 Adeney — Dissolved Gases and Fermentative Changes. 



reservoir. The middle portion of the vessel is 160 mm. long, and the upper end 

 has an inverted conical shape, which is 55 mm. long, the diameter increasing from 

 3 or 4 mm. at the lower, or narrow part, to 20 mm. at the mouth. 



Two platinum wires are sealed into the vessel in the position shown in the 

 drawing. 



The special shape given to the upper portion of the laboratory vessel enables 

 it to be easily connected, or disconnected with the burette. When the vessel is 

 placed in position, as represented in the drawing, the capillary branch tube, the 

 end of which is fitted with an indiarubber collar, tightly closes the narrower part 

 of this portion of the vessel, while the lower shoulder of the vessel rests upon a 

 shelf (shown in the drawing) which has somewhat the shape of a horseshoe. If 

 the space above the rubber collar at the end of the branch capillary tube be filled 

 with mercury or water, a perfectly air-tight joint is obtained. The joint may, 

 in fact, be made so staunch, that a vacuum can be maintained in the vessel, or, on 

 the other hand, explosions may be made therein without fear of loss. 



When it is desired to disconnect the laboratory vessel, its lower portion is 

 drawn forward sufficiently to clear the shelf, and it is then lowered to detach it 

 from the branch tube from the burette. 



By reversing these movements, the laboratory vessel may be again placed in 

 its position. The shape of the indiarubber collar is of importance ; its lower end 

 must be shaped so as to bear well on the sides of the contracted portion of the 

 laboratory vessel. The collar is easily given the necessary shape by means of a 

 red-hot iron wire. The lower end of the laboratory vessel is closed by a well- 

 fitting cork, through the centre of which passes a straight glass tube about 10 mm. 

 long and 3 mm. bore ; to the outer end of this a piece of stout indiarubber tubing, 

 about 15 cms. long and 1 mm. bore, is attached. 



When the cork is fixed into its place, the other end of this glass tube projects 

 into the laboratory vessel for about 2 ctms. A small Bunsen screw-clamp is 

 provided, with which to open or close the rubber tube when necessary. 



The glass tube supplies the means of introducing gaseous or liquid reagents 

 into the laboratory vessel, and I therefore jDurpose to call it the reagent tube. 



The side tube from the lower portion of the vessel is, as I have already stated, 

 connected by means of a rubber tubing, with a separate reservoir, which is 

 supported in a box,* and raised or lowered along guides fitted at the back of the 

 apparatus, by means similar to those already described as provided for the 

 reservoir to the burette. 



The shelf which supports the laboratory vessel is, in reality, a small bracket, 

 the vertical limb of which is provided with a tongue at the back, sliding in a 



* The position of this box is not quite correctly shown iu the chawing. Its true position will, however, 

 be understood from the dt.>scription in the Icttor-presa. 



