of Mineral Waters. 2ld 



(4, 5), a sil^df Capsule (6), some funnels (7), test glasses (8), test 

 tubes (9), and glass rods, filtering paper, a spirit (10), and art 

 Argand Lamp (11), a retort (12), and receiver (13), a cop- 

 per btaiu to sterve as sand-bath (14), a blowpipe (15), a thermo- 

 meter (16), a scale of equivalents (17), a dropping bottle (18), 

 a few watch glasses (19), a support for holding glasses over a 

 lamp (20), a small brass stand with rings (21), a tube with a 

 bulb in the centre and a pointed extremity, for drawing up small 

 portions of liquids (23), platinum pincers (24, 25) : a small 

 but good balance, with well-adjusted weights, is also requisite, 

 accompanied by a phial and counterpoise for taking specific 

 gravities ; and lastly, a small mercurial trough. There should 

 also be a plentiful supply of distilled water, a portion of which 

 should be contained in a dropping bottle. 



Sect. II. Examination of Mineral Waters by Tests. 



1. Tlie term mineral water is applied to those natural spring 

 waters which contain so large a proportion of foreign matter as 

 to render them unfit for common domestic use, and to confer 

 upon them a sensible flavour, and specific action upon the 

 animal frame. Their temperature is liable to considerable 

 variation, and is sometimes their principal character, as is the 

 case with the waters of Bath and Buxton ; but they are gene- 

 rally so far impregnated with acid or saline bodies, as to derive 

 from them their peculiarities, and in this respect may convent- 

 enily be arranged under the heads of carbonated, sulphureous, 

 saline, and chalybeate waters. The mere taste of the water 

 enables us to determine to which of these subdivisions, it pro- 

 bably belongs. 



2. In examining a mineral water, it is of importance to as- 

 certain its specific gravity, which gives us some insight into 

 the proportion of its saline ingredients, its specific weight as 

 compared with pure water, being of course augmented by its 

 foreign contents. Mr. Kirwan (Essay on Mineral Waters, p. 145.) 

 has given the following formula for calculating the proportion 

 of saline substances in a water of known specific gravity: " sub- 

 tract the specific gravity of pure water from that of the water 

 examined, and multiply the remainder by 1.4. Tlie product is 



Q 2 



