C 838 3 
to have hardly any Parts of Iron in it [Exp. 3. and 4.3. 
The Spirit, with which it abounds, [Exp. 5. and 6.3 
may, perhaps, be owing to a Fermentation of the 
Sulphur, which is continually flying off, as appears 
by the ftrong Smell of it, after it has. been for fame 
time covered up. And Mr. Cox has lately informed 
me, that a filver Cup, which has been often ufed 
in drinking this Water, has acquired a yellowifh 
Colour. 
The Ludus Helmontii affords nothing but Iron. 
Nor does the Clay, through which they dug, dif- 
cover any Salt in its Compaction. We may 
therefore conclude, that the Hill, which lies be- 
tween the old Wells and this new one, contains 
the Purging Salt, with which thefe Waters are im- 
pregnated. 
I do not find any material Difference between the 
old and new Waters, except in the Convenience of 
drinking them. The old Wells are at a Diftance from 
any Houfe, except fome few Huts, and expofed to 
the Rain and Land-floods, by which they are often 
injured : The new Well is a Mile or two nearer to 
London , well fecured from any injuries of the 
Weather. 
Dcember n. 1740, 
John Martyn- 
XXIII. An 
