5. Boracic acid has been found in some of the lakes of Italy, though, in the waters in which it has been ob served, it in general exists in a state of combination.
6. Sulphureous acid has been detected in some of the waters oh Italy near volcanoes.
7. Sulphuretted hydrogen is a very common ingre dient in mineral eaters. It was first discovered in them by Scheele.
8. Soda is the only alkali which has been found, in its free state, in mineral waters. Accordinq. to Dr. Black it exists in the waters of Geyser and Rykum, in Ice land.
9 Lime also, in its pure state, is said by some che mists to exist in mineral waters.
10. Silica exists in the waters of Geyser, and in many others. It was generally supposed that the earth was held in solution by soda; this however does not seem to be the case, as the quan'ity of alkali in the waters con taining silica is so trifling.
Nitric, carbonic, sulphuric, and muriatic acids, and sulphuretted hydrogen, ale frequently found in mine ral waters, in union with potassa and soda, with lime and magnesia, and with the oxide of iron. Baryta, alu rnina,and the oxide of copper, have also been found in combination with some of the above-mentioned acids, though less frequently than the other bases. Sub borate soda has likewise been detected in the lakes of Thibet and Persia; these waters, however, do not be long to those properly called mineral waters.
The 7:Prates .•re rarely found in mineral waters.
11. Nitrate of potassa has been detected in some of those ;• Ilring.rrt..ord in the salt springs in Germany.
12. Nitrate of lime was first discovered to exist in water by Dr. Home. It is is found also in some springs in the Deserts of Arabia.
Tile carbonates are perhaps the most frequent of the compound salts contained in mineral waters.
13 Carbonate of potassa has sometimes, though rare ly, been hound. When present, it is in small quantity.
14. Carbonate of soda is a much more abundant pro duction, icing contained in a great many waters.
15. Carbonate of ammonia is seldom detected.
16. Carbonate of lime, in union with an excess of car bonic, is perhaps the most common ingredient in mineral waters, few waters existing without it. 1000 parts of
water by weight, when they contain 2 of carbonic acid, can dissolve 2 of carbonate of lime. As the quantity of water increases, the carbonic acid necessary to hold the carbonate of lime in solution becomes smaller. What ever be the quantity of carbonic acid in water, it is able to hold the cat bonate of lime in solution, provided the carbonic acid exceed the weight of the lime.
17 Carbonate of magnesia is frequently found in mineral waters, also held in solution by an excess of acid.
18. Carbonate of alumina, according to Westrumb, exists in the waters of Weinberg and Pyrmont ; it is doubtful, however, if this be the state of combination of the alumina.
19. Carbonate of iron is often contained in mineral waters. When iron is present in water, it is almost always in union with carbonic acid; the carbonate being held in solution by an excess of acid.
The sulphates are not so frequently found as the car bonates.
20. Sulphate of soda, however, often occurs.
2 t. Sulphate of ammonia has been detected in some springs near volcanoes.
22. Sulphate of lime is a common ingredient in mine ral waters.
23. Sulphate of magnesia frequently exists. It is con tained in the waters of Epsom; hence the name of the salt Epsom Salt.
24. Sulphate of iron is often found in waters in the neighbourhood of volcanoes. It has also been detected in other waters, as in those of Horley Glee') by Dr. Garnet, and in the waters of Denmark by Bergman.
25. Sulphate of copper is a very rare production in mineral waters. It is found wily in those which issue from copper mines.
The muriates are very frequently observed in waters.
26. Muriate of potassa, however, rarely exists.
27. Muriate of soda, on the contrary, is found in al. most all mineral waters.
28. Muriate of ammonia has been detected in some lakes in Italy..
29. Muriate of lime and muriate of magnesia are often found.
30. Muriate of baryta and muriate of alumina, it is said, exist in sonic waters, they are however very rare ; the former has been detected by Withering, the latter by Bergman.