Account of a Boring for procuring Fresh Water. 
103 
abundant supply within a very few feet of the surface by the method, now so com- 
mon in England, of perforating to the springs with a borer, and keeping the hole thus 
made open with a cylinder of metal, terminating above in a shallow well of masonry. 
From the borings above alluded to, it seems, that the rock is at Calcutta about 140 
feet only from the surface, and that it contained much lime : it would be interesting 
to know, whether any other borings have ever been made, at no great distance E. or 
W. of Calcutta ; as from the results of such experiments the inclination of the rock 
might be traced, and the practicability of procuring good water at any place in the 
vicinity might be surmised. There is no basset of limestone, that I am aware of, on 
the western edge of the plain of Bengal, and this would seem to indicate, that the 
rock in question is only a partial formation and perhaps a thin bed only, such as is 
met with in the clays of the London Basin, but the nature, extent, and depth of the 
rock are points of considerable importance, which, however, I fear are not likely soon 
to be ascertained. 
I am, Sir, 
Calcutta, 1 Yours obediently, 
March, 1829. f A. N. 
Analysis of the Water drawn from a Well in Fort Wiliam, at the Depth of 70 Feet 
from the Surface ; by Dr. Win. Hunter. 
Agreeably to vour desire, I have drawn up as good an account, as the materials 
now in my possession will admit, of the experiments I made on the water sent by 
you to me in 1804. For reasons which I shall presently assign, the analysis was 
left unfinished, with the intention of repeating the operation from the beginning, 
which I never had leisure to do ; but I hope enough has been ascertained for pur- 
poses of real utility. 
I. 
1. The water was of a milky or opal colour; it had a muddy taste, and a slight- 
ly putrescent smell. 
2. No change was produced on litmus or turmeric paper by dipping them 
in this water, but Pernambuco paper had a slight violet tinge induced on it, and 
the blue colour was in some degree restored to litmus paper reddened by vinegar. 
3. Nitrate of silver produced a copious precipitate. 
4. On the addition of pure potassa, a cloud was suspended in the middle of the 
glass. 
5. Lime water struck a cloud. 
6. Muriate of barytes produced no effect. 
From these experiments it appears, 
1st. That a minute quantity of some earth was suspended in the water, and (by 
exp. 4. 5.) it appears probable, that this was earth ofmagnesia, and (by No. 5.) most 
likely carbonated. A small proportion of clay is indicated by the opal colour. 
2dly. That some putrid animal or vegetable particles had access by filtration to 
the water. 
3dly. That it contained a very small proportion of disengaged alkali (by No. 2.), 
unless the change of Fernambuco paper was produced by the carbonate of mag- 
nesia. 
4thly. (by No. 3.) That there was a considerable quantity of some muriate ; and, 
5thly. (by No. 5.) that there was no sulphuric acid, nor any of its combinations. 
IL 
1. Of this water 141b. 1 oz. avoird. were evaporated to dryness, and left a resi- 
duum of 220 grs. 
2. This being digested in rectified spirit of wine, filtered and evaporated to dry- 
ness, gave a residuum of 14J grains. 
3. On the residuum, insoluble in spirit of wine, were poured eight times its 
weight of distilled water ; this solution being slowly evaporated for several days 
without depositing any crystals was evaporated to dryness, and yielded 118^ grains 
of a salt in dry powder. 
4. The residuum, not soluble inspirit of wine nor in eight parts of distilled water, 
being well dried weighed 56J grains. 
The sum of these three portions falling short by 30J grains of the weight obtained 
by the first operation led me, as above stated, to suspect inaccuracy and tobreakoff 
the process, but not having had an opportunity of resuming it, 1 shall endeavour to 
