Adeney — An Apparatus for Gas Analysis, 8fc. 545 



the laboratory vessel may be again attached to the apparatus. 

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

 must be rounded off. It may be conveniently made in the labora- 

 tory, from the core obtained by cutting a hole in an ordinary cork, 

 by means of a cork-borer of suitable diameter ; one end of the core 

 will generally be found sufficiently rounded to suit the required 

 purpose. 



For some problems in gas analysis the laboratory vessel 

 may be employed in the ordinary way. The lower and open end 

 is immersed in a mercury trough, and may be filled from the trough 

 in the following manner. The stopcock is opened to the tube h, and 

 the reservoir raised until the burette is full of mercury ; the stop- 

 cock is then turned to open to the tube g, and consequently to the 

 laboratory vessel. The reservoir is now lowered slowly, and as the 

 level of the mercury in the burette sinks, it rises in the laboratory 

 vessel. The reservoir is lowered until the laboratory vessel is full. 

 The air that is drawn into the burette during the operation is driven 

 out into the atmosphere by opening the cock to the tube h, and again 

 raising the reservoir. When the burette is full of mercury, the 

 glass cylinder filled with water, and the pressure tube in proper 

 order, the apparatus may be used in a similar manner to that of 

 Frankland or Macleod. 



Since the apparatus, however, can be employed as an air-pump 

 similar in principle to Friedrichs' new pump, as well as for 

 measuring and analysing gases, its applicability to a great variety 

 of purposes becomes possible, if the laboratory vessel be furnished 

 with the means of filling it with mercury, as well as of adjusting 

 the level of mercury in it, independently of the burette. This 

 may easily be effected by closing the lower end of the vessel with 

 an indiarubber cork, and connecting it by means of the side tube 

 o to an independent adjustable reservoir which is raised and 

 lowered by means of a pulley and windlass m fixed to the back of 

 the stand, just as in the case of the reservoir furnished for the 

 burette and pressure tube. 



To provide the means for introducing re-agents into the 

 laboratory vessel, when it is modified as here described, the 

 cork which closes the lower end of the vessel is fitted with a 

 glass tube (which for the purpose of reference may be called the 

 re-agent tube) about 10 cms. long, and 2 mms. bore, one end of 



