2 Dr John Davy on the 



of which is used for drinking. This is the mineral water of 

 Nevis. I found its temperature 110'5° immediately under 

 the mouth of the pipe, through which it flows into the cistern. 

 It was perfectly clear, and free from any appearance of effer- 

 vescence or of disengagement of air. It had a just perceptible 

 taste, not to me disagreeable, and by some persons liked. 

 The water with which the baths are supplied, and this the 

 drinking water, are, I believe, from the same source, and of 

 the same quality ; the temperature of each depending on 

 circumstances of an accidental nature : I say, I believe, for 

 it may be otherwise, as I have examined only the water of 

 highest temperature, that used for drinking. 



The specific gravity of this water reduced to the tempera- 

 ture of 80°, I have ascertained to be 10-019. Though not 

 sparkling, this water is nearly saturated with carbonic acid, 

 and contains its own volume of the gas. 



From 44 cubic inches, that is about 11*120 grains of the 

 water, there were obtained, besides carbonic acid, 1*8 grains 

 of saline matter, readily soluble in water, chiefly bicarbonate 

 of potash, with a trace of muriate of magnesia, 1*3 of car- 

 bonate of lime, -77 grain of carbonate of magnesia, 1-6 of 

 silica, a trace of phosphate of lime, of sulphate of lime, and 

 of vegetable matter. I sought in vain to detect in it either 

 iodine or bromine. 



The vegetable matter, a kind of mucor, was found in bot- 

 tles of the water that had been kept many months, though 

 confined with glass stoppers. It appeared in the form of 

 minute delicate fibres, partly black, partly green, and when 

 spread out colourless. Under the microscope it was seen as 

 an irregular tissue of nucleated fibres, of an average width 

 of about jx>Vo of an inch. Occasionally after long keeping, 

 the water had a smell of sulphuretted hydrogen. This it may 

 have derived from the decomposition by the vegetable matter 

 of a little sulphuric acid in the minute portion of sulphate of 

 lime present. In one instance that I perceived the odour of 

 this gas, the water was confined by a common cork ; and, in 

 that instance, no sulphuric acid, after the sulphuretted hy- 

 drogen was perceptible, could be detected in the water by 

 the test of muriate of barytes. 



