1823.] 
order, and, if not cured, necessarily 
fatal sooner or later; it is also rather 
frequent, and by the common methods 
almost always incurable: therefore, to 
introduce a medicine to public notice 
which will invariably mitigate the suf- 
ferings of epilepties, and generally 
eure them, will be attaining no mean 
end. This is my object in writing 
this letter; which, 1 trust, will gain 
me Dr. Uwins’ excuse for thus pub- 
licly controverting his opinion. 
1 might add, that the extraordinary 
effects of the above medicine in epi- 
lepsy,—which is confessedly anervous 
disorder,—naturally led to its employ- 
ment in cases of great nervous depres- 
sion, and in convulsions; in a few of 
which it has been used with the most 
gratifying result. 
German Place, 
Brighton ; Feb. 1823. 
onheeestin 
To the Editor of the Monthly Magazine. 
SIR, 
OUR respectable correspondent, 
Mr. J. Fitch, who in page 321 
ef your last volume had judiciously 
ealled the attention of nautical men 
to the principle of filtration by ascent, 
as applicable to the purifying of foul 
water at sea, has since done me the 
honour, in page 400, to notice a com- 
munication of mine, inserted in page 
200. Yo Mr. Fitch I should earlier 
have replied, had not his concluding 
paragraph lave afforded reason to 
hope, that ere this Capt. Layman 
would have stated a few more particu- 
lars (in addition to those in p. 122 of 
the same volume,) as to the circum- 
stances under which the Captain pro- 
cured fresh water for his ships, on the 
coasts of Malabar and of Sapy, by 
sinking holes in the sandy sea-beach. 
The water thus obtained by Capt. 
L. he assumed to be sea-water, freed 
from its saltness and bitterness, by 
means of filtration through the sand; 
and hence, in the communication re- 
ferred to, he appears to infer, and give 
nautical men reason to expect, that 
the same means would prove success- 
ful for the procuring of fresh water in 
any part of a sandy beach, wherever 
situated. On both of these points,— 
viz. as to the source of the fresh wa- 
ter, and as to the general applicabi- 
lity of this method of procuring fresh 
water, I have endeavoured to show 
that Capt. L. has been mistaken, and 
at the same time have tricd, by point- 
ing out the source and principle of the 
T. J. GRAHAM. 
Mr. Farey in answer to Mr, Fitch and Capt. Layman. 
37 
supply, to enable nautical men to avail 
themselves of such a supply, where- 
ever attainable. 
The objections are two, which Mr. 
Fitch has, im page 400, urged against 
my explanation of the phenomenon, 
viz, Ist. That Lord Bacon and himself 
have considered the «bbing and flow- 
ing of water in a weltor hole on the 
sea-shore, as the tide fell or rose, to 
be evidence that the water in such 
well or hole is sea-water; and 2d. 
That the brackishness, often, of the 
water so obtained, is evidence that 
the whole comes from the sea. Mr. 
F.’s words are, ‘‘ Its ebbing and flow- 
ing with the tide, if not corclusive, is 
an important fact towards proving, 
that the fresh water thus obtained is 
sea-water, purified by percolation 
through the sand; and again, speak- 
ing of the brackishness, he says, ‘ This 
appears to be an additional proof that 
the water in the pits is sea-water.” 
I have already, in page 202, noticed 
the want of any chemical principle or 
experimental fact, to prove that wa- 
ter, containing saline and bitter mat- 
ters in solution, that is in chemical 
combination, (as is the case with re- 
gard to sea-water,) can in any case be 
freed therefrom by mere filtration; 
and [ would now remark, that tbe very 
rapid filtration here contended for 
would scarcely be sufficient to free 
muddy water from its impurities, only 
mechanically suspended in it; and 
again, that sea-water, as often passed 
into the sand, and being capable of 
precipitating and leaving there all 
its matters previously held in selu- 
tion, as the tide has risen times, must 
long and long ago’ have close filled 
every interstice in such sand, and fil- 
tration therein would now be imprac- 
ticable ; because, let it be observed, 
the water, returning on the cbb of the 
tide, cannot be supposed capable of 
again dissolving or taking up its salt 
to bear it to the sea, without render- 
ing its previous precipitation an ab- 
surd supposition; in fine, the great 
Lord Bacon knew or considered not 
the essential differences which exist 
between chemical solution and mecha- 
nical mixture, or he would not have 
advanced the doctrine quoted from 
his works. 
In order to show that the ebbing and 
flowing of fresh water in a well near 
the sea, (which is a very common 
fact, and has often been noticed, as I 
shall further mention,) is no proof of 
such 
