the Mineral IVaters of Dunblane and Pitcaithly. 265 



ncss. As procured from the principal poo! at which it issues, 

 it is free from smell ; procured, liowever. from some other pools, 

 at the distance only of a few feet, its smell is slightly sulphureous, 

 probably owing to iniprcs:nation from matter at or immediately 

 under the soil. Its sensible operation on the system is that of 

 a diuretic and purgative. The former effect is usually obtain.ed, 

 when a quantity is taken by an adult, from an Englisii pint to a 

 quart ; the latter, when more than a quart is taken. The spe- 

 cific gravity of the water is 1*00475. It sufifers no change in 

 its sensible qualities from exposure to the air. 



The state of the spring is at present such, that any gaseous 

 impregnation of the water cannot be determined with precision. 

 Bubbles of air frequently rise from the bottom of the pool, but 

 this is merely atmospheric air: transmitted through lime-water, 

 it produced no sensible milkiness ; nor does the water appear to 

 contain any free carbonic acid. 



The usual reagents present with the water the following ap- 

 pearances : 



1. The colours of litmus, violet, and turmeric, are not sen8ii)ly 



affected. 



2. Muriate of barytes produces an immediate turbidness, and 



rather copious precipitation, which is very slightly, if at all, 

 removed by nitric acid. 



3. Nitrate of silver gives a very dense and abundant precipitate. 



4. Water of potash produces a turbid appearance, not very con- 



siderable. 



5. Carbonate of potash throws down an abimdant precipitate, 



which disappears with effervescence on adding nitric acid. 



6. Lime-water causes no change. 



7. Ammonia does not cause any precipitation, nor docs it even 



impair the transparency of the water. 



8. Oxalate of potash, or of ammonia, occasions a copious pre- 



cipitation. 



9. Tincture of galls has no immediate sensible effect ; but after 



an hour or two a purplish tint is exhibited, which deepens 

 from exposure to the air, and inclines to olive-green. 

 These results estaijlish the following conclusions: 

 Exper. 1. proves that no free acid or alkaline matter is present, 



nor any alkaline carbonate. 

 Exper. t. denotes the presence of sulj)hiiric acid. 

 Exper. 3. indicates the presence of muriatic acid. 

 From Exper. 4. and 5. may be inferred the presence either of 



lime, or magnesia, or both. 

 P'xpcr. (5. and 7. prove that magnesia is not present, nor argil. 

 Exper. 8. proves tlie presence of lime. 

 £xper. 9. indicates a minute portion of iron. 



The 



