Intelligence and Miscellaneous Articles. 329 



twice, and terminates in the large empty flask. To adapt it more 

 easily, it may be cut anywhere in the middle, and the two parts 

 connected by caoutchouc. The two tubes dipping in the liquid a 

 are drawn out at their lower ends into fine, somewhat laterally curved 

 points; the tube be contains, in the expanded portion bd, which is 

 from three-quarters to an inch in width, well-burnt lime, which may 

 be readily moistened with water, from d to e, asbestos, or fragments 

 of pumice-stone, drenched with sulphuric acid, and separated from 

 the lime by a light stopper of asbestos; the small Woulf's flask 

 contains lime-water. 



The analysis is now performed in the following manner : — A small 

 quantity of sulphuric acid is poured into the flask a through the 

 funnel-tube, the stopcock g being closed ; as this will not descend 

 of itself, it is made to do so by drawing gently with the mouth at h. 

 The evolution of gas, which is rendered perceptible by the ascending 

 bubbles, and by the air passing through the lime-water in/, is now 

 waited for ; another portion of acid is then added, and this continued 

 until it may be assumed that a tolerable excess of acid has been in- 

 troduced. This being done, some water containing a little caustic 

 potash in solution is allowed to flow into the flask by opening the 

 stopcock g, whereby a current of air is passed through the vessel a, 

 which carries the carbonic acid, contained partly in the liquid partly 

 in the upper space of the vessel, into the tube b e ; but since this 

 would never be completely effected without the application of heat, 

 the vessel a towards the end of the experiment is immersed in a small 

 dish filled with water, which is kept warm over a small lamp as long 

 as is found requisite. 



It is best to regulate the current of air so that about 2 bubbles of 

 gas pass through the lime-water in a second. It will however never 

 be found to become in the least turbid. It is scarcely necessary to 

 observe that the object of the sulphuric acid in b c is to retain the 

 moisture carried by the gas from a ; also that the potash added 

 to the water which flows into the large flask is to absorb the car- 

 bonic acid of the atmospheric air ; and, lastly, that, the increase in 

 weight of be yields the result sought for. 



Phil. Mas. S. 3. Vol. 29. No. 194. Oct. 1846. Z 



