M I N 



389 



Mineral periled to the proper strength, and remove the carbonic 

 wter. ^ aru j sulphuric acids by means of nitrate of baryta, and 

 s """"""* ' then add nitrate of silver to it, by which we ascertain 

 the quantity of muriatic acid, (61 ). 



By these different steps we ascertain the quantity of 

 the different ingredients. We must next ascertain the 

 state of combination in which they existed. This is 

 done, by supposing that the ingredients were so united 

 as to form the most soluble salts. Should other sub- 

 stances, besides these mentioned, be supposed to exist 

 in the water, as potassa or alumina, they must be detect- 

 ed by their proper test, and their proportions ascertain- 

 ed. These, it is supposed, are likewise so combined, 

 as to form with the acids the most soluble compounds. 

 Thus in his experiments on sea water, Dr. Murray 

 found that a pint of this fluid contained, 



Lime 2.9 



Magnesia 14.8 



Soda 96.3 



Sulphuric acid . . . .14.4 

 Muriatic acid .... 97.7 



226.1 



These, he inferred, existed in the water in the state of 

 muriate of soda, muriate of lime, muriate of magnesia, 

 and sulphate of soda. The quantity of sulphate of so- 

 da equivalent to 1 4.4, of sulphuric acid is 25.6 ; the re- 

 mainder of the soda 85.1 is united with 74.2 of muria- 

 tic acid, to form 159.3 of muriate of soda. The quan- 

 tity of muriate of lime, equivalent to '..'<> of lime, is 5.7- 

 The 14.8 of magnesia is combined with the remainder 

 of the muriatic acid to form 353 muriate of magnesia. 

 The saline contents, then, according to this way of de- 

 termining the compounds, are 



M I N 



Muriate of soda 159.3 



Muriate of magnesia 95.5 

 Muriate of lime 5.7 



Sulphate of soda 25.6 



Mineral 

 Wateri. 



226.1 



In the same way, having ascertained the proportions 

 of the different ingredients in any mineral water, the 

 quantities of the compounds which they form may be 

 ascertained. 



If this view of the constitution of mineral waters 

 be correct, the component parts of those analysed will 

 be very different from what has been stated in the fore- 

 going Table, these having l>een ascertained by the eva- 

 poration of the fluid, and by the other methods usually 

 followed in the analysis of mineral waters. Thus those 

 which have yielded sulphate of lime and muriate of so- 

 da, it is inferred, contain muriate of lime and sulphate 

 of soda, the two former having been generated during 

 the evaporation by the decomposition of the latter. The 

 quantities of the substances contained in the water may 

 be ascertained, by finding the equivalents of the different 

 compound*. Thus 100 of sulphate of lime are equiva- 

 lent to 8 1.5 of muriate of lime; and 100 muriate of soda 

 are equivalent to 122 sulphate of soda *. 



The mode of analysing mineral waters recommend- 

 ed by Dr Murray, is one attended with much less la- 

 bour, and, it is probable, lead* to results at least as ac- 

 curate, if not more so, than those obtained by any of 

 the other methods of analysis. A strong argument in its 

 favour, isits detecting in mineral waters substances which 

 act powerfully on the animal system, and thus enabling 

 us to account for the medicinal effects of some of them, 

 which cannot be done by the other modes of analysis. 



MINERALOGY. 



A I INCBALOGY is that branch of natural history which 

 makes us acquainted with all the properties and rela- 

 tions of minerals. It i* divided, by Werner, into se- 

 veral branches, or doctrines, viz. : Oryctognosy, geo- 

 gnosy, mineralogical chemistry, raineralogical geogra- 

 phy, and economical mineralogy. Oryctognosy, (or 

 mineralogy, commonly so called,) arranges and des- 

 cribes simple minerals, according to their external cha- 

 racters ; geognosy makes us acquainted with the struc- 

 ture, relative position, materials, and mode of forma- 

 tion of mountain rocks, or those mineral masses of 

 which the crust of the earth is composed ; mineralogi- 

 cal chemistry enumerates the various chemical proper- 

 ties and relations of minerals ; mineralogical geography 

 delineates the geographical distribution of simple and 

 compound minerals over the face of the earth ; and eco- 

 nomical mineralogy teaches us the various uses of mi- 

 Bends, whether simple or compound. 



In the general view of mineralogy adapted to tin- 

 nature of an Encyclopaedia, we cannot use this arrange- 

 ment of Werner's. Wr shall consider mineralogy un- 

 der two heads ; vix. Geognosy and Oryctognosy ; and 

 view them in such a manner as to include the most im- 



portant details which belong to the doctrines of chcuii- 

 col, geographical, and economical mineralogy. 



GEOGNOSY. 



CHAP. I. Hittory. 



This important branch of natural history makes us 

 acquainted with the structure, relative position, mate- 

 rials, and mode of formation of the mineral masses of 

 which the crust of the earth is composed. The term 

 geognoty is derived from the Greek words y*, the earth, 

 and y.i,-, knotrledge. It has been confounded with 

 urology, which instructs us regarding the physiognomy 

 of mountains ; with geogony, which is purely hypothe- 

 tical, consisting of very abstract speculations regarding 

 the original formation of the earth; also with geology, 

 which, however, has a more extensive signification, for 

 the word **/ comprehends the whole science, or ra- 

 tionale of any subject ; and therefore geognosy is only a 

 branch of geology. Geology, imli-fd, according to Wer- 

 ner, comprehends not only geognotu, but also geogra- 

 phy, hydrography, meteorology, ana geogony. 



* Forfadiof i 



, UM ml* of (quintals sf WsibMon is dmirtblj tdipted, M bj it a great dcl of calculation i* HTCJ. 



