61 



opaque glass so as to make the divisions on the burette distinctly 

 visihlc. The bottom of the burette is connected by an elastic 

 tube with a level bottle filled two-thirds with water ; the top 

 end is connected by a glass capillary bent at a right angle, and 

 ending in a three-way cock. This tube carries at a right angle 

 three glass taps, each possessing capillary tubes, and connected 

 by india-rubber joints with the three U-shaped absorption 

 vessels filled with bundles of glass tubes. The first of these is 

 filled with a solution of caustic potash, the second with an alka- 

 line solution of pyrogallol, and the third with a strong solution 

 of cuprous chloride in hydrochloric acid. Copper spirals are 

 placed in the glass tubes in this vessel so as to keep the solution 

 unchanged. These solutions are for the absorption of carbon 

 dioxide, oxygen, and carbon monoxide respectively. The outer 

 ends of the absorption vessels are closed by tubes communicating 

 with an empty gas bag. The apparatus may be completely 

 closed by sliding doors at the back and in front. 



100 c.c. of gas at normal pressure are drawn into the burette. 

 The gas is then forced backwards and forwards between the 

 burette and the absorption vessel nearest to it, containing caustic 

 potash ; the carbon dioxide is absorbed, the gas is finally all 

 drawn into the burette and the reading taken, the levels of the 

 water in the burette and level bottle being made the same. 

 This reading indicates directly the per-centage of carbon 

 dioxide. ID. the same way the oxygen is absorbed in the centre 

 vessel and the carbon monoxide in the third. The unabsorbed 

 residue represents the nitrogen. 



The whole apparatus is specially intended for the analysis of 

 combustion gases. 



(See Winkler's Technical Gas Analysis.) 



197. Winkler's apparatus for determining the amount 

 of carbon dioxide present when ventilating mines. 



B. 53. 1884. Made by F. HugersJioff, Leipsic. 



This apparatus is used for estimating relatively small quan- 

 tities of carbon dioxide. The graduated measuring tube is 

 closed at the top by a three-way cock. Its capacity is 100 c.c. ; 

 most of this is contained in the globular part. The narrow 

 cylindrical part only contains 5 c.c ., and is divided into 

 twentieths of a cubic centimetre. The lower end of the burette 

 is connected by a narrow elastic tube with the level-bottle to the 

 right containing pure water; from the upper part a glass 

 capillary tube leads to the absorbing vessel which is filled with 

 a solution of caustic potash up to the mark. The burette is 

 filled with the gas to be examined through the pinch-cock 

 attachment of the three-way cock. The apparatus is manipu- 

 lated in a similar manner to Orsat's, described above. 



(See Winkler's Technical Gas Analysis.) 



U 64846. E 



