210 On the spontaneous heating of Brine. [March, 



It is remarkable that the probe indicated no signs of a heating influ- 

 ence affecting the water in the large reservoir at Narainpore on the 

 19th November though the specific gravity of the brine near the 

 bottom was little less than that of the water in the long reservoir 

 at Batya Ghat on the 5th November, its mean spec. grav. being also 

 considerably higher than the mean of the latter. Moreover the heat- 

 ing influence was scarcely traceable in the covered brine reservoir at 

 Narainpore on the 19th November, which perhaps may be accounted 

 for by the large previous expenditure of brine, say about three-fourths 

 of its original contents, the consumption of which had been replaced to> 

 within a foot of the general level by filtration from the ground and 

 leakage at the gate communicating with the adjoining terrace and brine 

 fields; whereas the expenditure of brine in the contiguous open round 

 reservoir otherwise similarly situated, was but half of the original con- 

 tents up to the middle of January, its entire volume being about 170,000 

 cubic feet, while the covered reservoir contained only about 50,000. In 

 these two reservoirs all the brine when first let in was of a high degree 

 of saturation, ranging from 1170 to 1200 sp. gr. and consequently con- 

 taining little or no sulphate of lime, which ingredient in the composition 

 of sea water, I have observed at Balya Ghat, is always deposited upon 

 the terraces there, considerably before the brine begins to deposit its 

 sulphate of soda. But this was not the case with respect to the brine 

 in the large reservoir at Narainpore, nor in that of a longer narrow 

 one at Balya Ghat, except perhaps a small proportion of the latter, both of 

 which were charged with brine of only 1070 to 1085 sp. gr., a much 

 higher degree however than that of the contents of the long reservoir 

 in any previous year; and in both of them the water had remained undis- 

 turbed, except by the action of the atmosphere ; yet in one of them a high 

 degree of heat was observed, and in the other where I should sooner 

 have expected to find it, no indication of heat was perceived beyond the 

 probable temperature at which it was filled in June. 



In order to ascertain however whether any fermentation and disen- 

 gagement of heat takes place on the mixture of saturated brine with 

 brine of a weaker degree, I lately procured from Balya Ghat some 

 bottles of brine of different degrees of saturation, with which the follow- 

 ing experiments were tried. 



Is* Experiment — Half a pint of saturated brine sp. gr. 1216, tempe- 

 rature 82.5 mixed with about the same quantity of brine of sp. gr. 1069, 

 temperature 81.2. Result, temperature 82.2 and no effervescence after 

 standing some minutes. 



2nd Experiment — Same quantities of brine sp. gr. 1216, tempera- 



