26 Mr. G. A. Prinsep on the spontaneous heating of Brine 



whole of the preceding observations. I have put them to- 

 gether for the purpose of suggesting to other inquirers cer- 

 tain sources of agency which it would appear must be neces- 

 sarily followed by certain effects. That these should become 

 sensible in themselves is what one should naturally expect ; 

 but if it should prove otherwise, it is worth while to inquire 

 how it happens that they are lost. Whether, or how, they 

 can be further traced 1 cannot now inquire ; but it set^ms 

 reasonable to suppose that considerations involving time and 

 space to the amount of two seconds, and 400,000 miles, 

 ought not to be neglected as indifferent to investigations, 

 where appreciable phsenomena supply measurements, in the 

 case of a wave of light, to the ten millionth part of an inch, 

 and the quadrillionth of a second. 



I remain, Gentlemen, yours, &c. 

 November, 1838. J. S. W. 



V. Oil a remarkable Heat observed in Masses of Bridie Jcept 

 for some time in large Reservoirs. By G. A. Prinsep, 

 Esq.* 

 TN the course of my experiments of several years in the 

 manufacture of salt at Balya Ghat, on the salt-water lake 

 east of Calcutta, I have sometimes observed a high degree of 

 temperature at the bottom of the brine reservoirs after they 

 had been filled for some weeks with brine of less than one 

 fourth saturation. But as the greatest heat observed did not 

 exceed 104-° Fahr. which was under the maximum heat of the 

 brine on the terraces, whence the reservoirs had been filled, 

 I supposed the high temperature to be merely that of a warm 

 stream of water let in at the hottest part of the day in May or 

 June, and remaining below and unmixed with the cooler sur- 

 face water, of less specific gravity, afterwards admitted. This 

 opinion was strengthened by the gradual reduction of the 

 temperature below to nearly that of the surface, before the 

 end of the rainy season. I have frequently bathed in one of 

 the i-eservoirs (about 550 feet long, 35 feet wide at top and 7 

 or 8 feet deep), in September and October, and have found the 

 temperature of the water then pretty equal throughout. But 

 on plunging into the same reservoir on the 17th September 

 last, I was surprised to find the tempei'ature near the bottom 

 so warm as to be intolerable to the feet. Still however I 

 imagined that the heat was only that which the sun had im- 

 parted to the terrace brine in the very sultry weather of Jime 

 last, (1837) when I had 120° registered (4th June, 4 p. m.) for 



• From the Journal of the Royal Asiatic Society of BenKal, vol. vii. 

 p. 207. 



