Mineral JVaters at Cheltenham. 89 



Experimeril XXVIII. — To ascertain the respective pro- 

 portions of these gases contained in a given bulk ot" water, 

 924 cubic inches of the sulphuretted water taken fresh from 

 the spring head, were introduced in ajar, connected with a 

 Woulf 's apparatus in the ordinary manner ; the first of liie 

 three-necked bottles of the apparatus was filled with a solu- 

 tion of acetate of lead ; reiTdered acidulous by the addition of 

 acetic acid ; the second contained lime water. On applying 

 heat to the water in the jar, a precipitate was soon deposited 

 in both the bottles : the solution of acetate of lead acquired 

 a velvet black colour; and the lime water in the second bot- 

 tle became milky. The sulphuretted hvdrosrcn gas was thus 

 made to combine with the oxide of lead ; and the carbonic 

 acid being prevented from forming a carbonate of lead on ac- 

 count of the excess of acetic acid, it passed through the me- 

 tallic solution unaltered, and united with the dissolved lime 

 in the second bottle. Thus both gases were distinctly ar- 

 rested by different agents, and in different vessels. To ren- 

 der this experiment as conclusive as possible, like quantities 

 of sulphuretted water were treated in the same manner, with 

 the exception of substituting only oneWoulf's bottle nistcad 

 of two in the arrangement of the apparatus, the bottle con- 

 taining acetite of lead with excess of acid, and lime water 

 alternately. The production of hvdro-sulphuret of lead, and 

 carbonate of lime was uniformly the same with variations not 

 amounting to the .^-^dth part of a srraln. 9'2i cubic inches 

 of the sulphuretted water treated in this nnur.ier, yielded 78 

 grains of hydro-sulphuret of lead, which are equal (accord- 

 ing to Westrumb) to 40 cubic inches of suipliurclied hv- 

 drogengas*. The carbonate df lime obtained from 2.^1 

 cubic inches of water, calculated in the usual niinncr, indi- 

 cated 7 -*;5- ciil)lc inches ot carbonic acid gas. One gallon of 

 the sulphuretted saline water theretore contains 



Cubic inclics. 



Sulphuretted hydrogen gas 1 i-O 



Carbonic acid gas - - 7'9 



18 9 



Wistrumb? Bcschrcibunp dcr Gcsund Erunneu, 180.5, p. 150. 



Ai\'ALYS!S. 



