THE ISLAND OF CEYLON. 
a blackish tinge, which shews it to be slightly impregnated 
with iron. 
On mixture with a solution of silver in nitrous acid, 
some precipitate of luna cornea, muriat of silver, was pro- 
duced. This shews it to contain a very small portion of 
sea salt; but not more than the common waters of Trin- 
c.omalee, on which the solution of silver had the same 
effect, with this difference, that the precipitate from the 
water of the hot wells was blackest, probably from the 
impregnation of iron . 
These experiments were made at the wells, with water 
from those of the highest and of the lowest temperature, on 
the 4th of July 179 8 > when the heat of the atmosphere 
was at 91 degrees. They were also repeated upon the 
water after it was brought to Trincomalee, with the same 
result. 
From hence it would appear, that the hot wells of Cannia 
possess few mineral qualities, or any virtues besides their 
heat, which is of a temperature not unfavourable for hot 
bathing. 
For many complaints, drinking of hot water is recom- 
mended, and for this purpose as well as for bathing, a 
hot spring is always preferable to water heated artificially, 
because it is always of a fixed degree of temperature. 
