vol. xx. (i) MINERAL WATERS NEAR GLOUCESTER 
3i 
There is an impression among medical men that artificial 
waters containing the bodies enumerated above are far less 
potent as curative agents than the natural waters, and if 
this be so, the practice at some Spas of boiling down to con- 
centrate seems unwise. Some light may be thrown upon this 
subject by the discovery of numerous radioactive bodies loosely 
referred to as Radium. These were first proved to exist in the 
waters at Bath, but within a few months of this discovery I 
was requested by a client at Llandrindod Wells to examine the 
waters on the Rock Park Estate. I had special plant erected 
and operated on 500 gallons of water, from which I obtained 
enough radioactive matter to impress a photographic plate 
through a piece of cardboard one-sixteenth of an inch tlfick. 
On my return to Gloucester I operated on our spa w r aters, 
and established the fact that they also contained radioactive 
matter. 
Possibly the superiority of natural medicinal waters over 
those artificially prepared is due to their containing this 
mysterious radioactive matter. It may help us if we examine 
the composition of some typical medicinal waters, and I select 
for this purpose tu r o at Llandrindod Wells. (Table I.) 
I am not responsible for the names given to them, these 
were fixed by the proprietor of the Wells. 
We first notice the comparatively small amount of salt 
which is a characteristic of the best waters in this district. 
The presence of calcium salts is injurious, but this is com- 
pensated for by the Lithium, Thallium, and Magnesium. 
As to the Gloucester Spa w r aters, I may mention that I 
have made analyses of these, and select those of 1905 as fairly 
representing their composition, which varies very much owing 
to dilution with w r ater from the superficial beds. (Table II.) 
A glance at these will show the presence of bodies having 
therapeutic value, notably Sodium and Magnesium Sulphates, 
Magnesium Carbonate, Iron Salts, and Sulphuretted Hydrogen. 
Nine 3-ears afterwards, in 1914, I again made an anal)-sis 
of No. 2, and give the results in Table III. 
The enormous increase in common salt is very striking, 
there is also a diminution in the Sodium Sulphate. These are 
