MODIFICATION OF WARINGTOX 4OI 



The upper vessel consists of a similar bottle standing upright and 

 containing the hydrochloric acid required to act on the marble. 

 The two vessels are connected by a glass tube passing from the 

 side tubule of the upper vessel to the inverted mouth of the lower 

 vessel. The acid from the upper vessel thus enters below thr 

 marble. Carbon dioxid is generated and removed at pleasure 

 by opening a stop-cock attached to the side tubule of the lower 

 vessel thus allowing hydrochloric acid to descend and come in 

 contact with the marble. A good Kipp's generator of any ap- 

 proved form may also be used instead of the simple apparatus 

 above described. 



The fragments of marble used are previously boiled in water 

 in a strong flask. After boiling has proceeded for some time, a 

 rubber stopper is fixed in the neck of the flask and the flame 

 removed. Boiling will then continue for some time in a partial 

 vacuum. 



The hydrochloric acid is also well boiled and has dissolved in 

 it a moderate quantity of cuprous chlorid. As soon as the acid 

 has been placed in the upper reservoir, it is covered by a layer 

 of oil. The apparatus being thus charged is at once set in active 

 work by opening the stop-cock of the marble reservoir ; the acid 

 descends, enters the marble reservoir, and the carbon dioxid 

 produced drives out the air. As the acid reservoir is kept on a 

 higher level than the marble reservoir, the latter is always under 

 internal pressure, and leakage of air from without, into the ap- 

 paratus, can not occur. 



The presence of the cuprous chlorid in the hydrochloric acid 

 not only insures the removal of dissolved oxygen, but affords an 

 indication to the eye of the maintenance of this condition. While 

 the acid remains of an olive tint, oxygen is absent; but should 

 the color change to a blue-green, more cuprous chlorid must 

 be added. All the reagents employed should be previously boiled. 



In order to secure absolute freedom from air, the following 

 modifications on the above process have been adopted by War- 

 ington. The apparatus having been mounted as described, the 

 funnel-tube attached to the bulb retort is filled with water, and 

 the apparatus connected with the carbon dioxid generator. Car- 



