WATER. 



quantity. If fulphurous aeid be prefent, the above ftep is 

 unneccffary, for fulphuretted hydrogen never exifts in water 

 containing this acid. Sulphurous acid may be feparated by 

 introducing into the gafeous mixture a quantity of the 

 peroxyd of lead, in a ftate of powder. This will gradually 

 abforb the whole, and the diminution of bulk, as before, 

 will denote its quantity. The introdudion of a little potafh, 

 after this, will abforb the carbonic acid. The remaining 



The oxygen may be fe- 



for fome days to the air, and mixing with it a portion of 

 alumina. The oxyd of iron and fulphate of alumina are 

 precipitated together, and may be eafily feparated, and the 

 quantity of iron afcertained. 



5. if muriate of potafh or foda exift alone in water, its 

 quantity can be readily eilimated by precipitating the 

 muriatic acid with the nitrate of filver. The fame procefs 

 may be followed, if the alkaline carbonates be prefent ; 

 only thefe carbonates muft be previoufly faturated with ful- 



gafes muft be oxygen and azote ,„ . ■ ^ , r > .• lti, 



parated by introducing a piece of phofphorus, or by other phuric acid, and, inftead of uiing the mtrate, the fulphate 

 well-known eudiometrical means ; and the azote will remain "f <->l"- - t- ^^ — l^^.H 



laft of all, unaffefted by any of thefe proceffes 



2. The e.irthy carbonates, if any be prefent, are firft to 

 be feparated by boiling a given portion of the water for a 

 quarter of an hour. The precipitate thus obtained may 

 confift of a mixture of the carbonates of lime, of magnefia, 

 of iron, and of alumina, and even of the fulphate of lime. 

 Suppofing all thefe to be prefent, the precipitate is to be 

 treated with dilute muriatic acid, which vvill diffolve the 

 whole, except the alumina and fulphate of lime. Dry this 

 refiduum in a red heat, and note the weight. Then boil it 

 in a folution of carbonate of foda ; faturate the foda with 

 muriatic acid, and boil the mixture for half an hour : car- 

 bonates of lime and alumina will be precipitated ; the hme 

 may be then diffolved by acetic acid, while the alumina will 

 remain ; and thus the weight of each may be afcertained. 



The muriatic folution contains lime, magnefia, and iron. 

 To feparate thefe, add ammonia, which will precipitate the 

 iron and part of the magnefia. Dry the precipitate, and 

 expofe it to the air for fome time in a temperature of about 

 200°. The magncfii may be then feparated by acetic acid, 

 and the acetate thus formed is to be added to the muriatic 

 folution. The iron is now to be rediflblved in muruitic 

 acid, precipitated by an alkaline carbonate, and dried and 



weighed. . . ^ , . 



Muriate of lime and magnefia ftill remain in folution. 

 To feparate them, add fulphuric acid as long as any pre- 

 cipitate appears, then heat the folution, and concentrate. 

 The fulphate of lime thus obtained is to be heated to red- 

 nefs, and its weight afcertained. Laftly, the magnefia 

 may be feparated by an alkahne carbonate, or, what is 

 much better, by the phofphate of ammonia. 



3. To afcertain the quantity of the alkaline carbonates, 

 fuppofing them to exift in waters, determine how much of 

 any dilute acid, whofe ftrength has been previoufly carefully 

 afcertahied, is neceffary to faturate them ; and from this the 

 quantity of alkali can be readily eftimated. 



4. The alkaline and earthy fulphates may be eftimated by 

 the following methods. 



The alkaline fulphates may be determined by precipi- 

 tating their acid by means of the nitrate of barytes, having 

 previoufly feparated all the earthy fulphates. 



Sulphate of lime is readily eftimated by evaporating the 

 water to a few ounces, the earthy carbonates being pre- 

 vioufly faturated with nitric acid, and precipitating the ful- 

 phate of lime by means of dilute alcohol. 



If the fulphate of magnefia or alumina be the only ful- 

 phate prefent, the quantity of either can be readily eftimated. 

 If they exift together, the two earths may be precipitated 

 by foda, and afterwards feparated by acetic acid in the 

 manner above-mentioned. If fulphate of lime be alfo pre- 

 fent, this may be previoufly feparated in a great degree, as 

 above ; or, what is preferable, the lime may be precipitated 

 by an alkali along with the other earths, and afterwards 

 Separated. The fame holds good alfo with the fulphate of 

 iron ; or the iron may be feparated by expofing the water 



of filver is to be employed. 



If the alkaline muriates exift along with more or lefs of 

 the earthy muriates, or with the muriate of iron, without 

 any other falts, the whole of the earths may be feparated 

 by barytes water, and their quantities eftimated as before. 

 To difcover the proportion of the alkaline muriates, the 

 barytes is to be feparated bv fulphuric acid, and the muriatic 

 acid expelled by heat. The quantity of the alkaline mu- 

 riates may be then afcertained by evaporation. 



When fulphates and muriates exift together, they may be 

 feparated by evaporating the whole to drynefs, and diftblving 

 the earthy muriates in alcohol ; or, when the water has 

 been duly concentrated, by precipitating the fulphates with 

 the lame fluid. 



When alkaline and earthy muriates exift with fulphate of 

 lime, this laft fait is to be decompofed by means of the 

 muriate of barytes. The eftimation is then to be condufted 

 as if nothing but muriates are prefent, only the proportion 

 of muriatic acid which united in the muriate of barytes, 

 added, muft be allowed for. 



When muriates of foda, magnefia, and alumina, are pre- 

 fent, together with fulphates of lime and magnefia, the water 

 is better examined by two diftinft operations. To one por- 

 tion add carbonate of magnefia, till the whole of the lime 

 and alumina be precipitated. Afcertain the quantity of 

 lime, which gives the proportion of fulphate of lime. Pre- 

 cipitate the fulphuric acid by muriate of barytes : this gives 

 the quantity contained in the fulphate of magnefia and ful- 

 phate of lime ; and the quantity of fulphate of lime being 

 previoufly known, that of the fulphate of magnefia can be 

 eafily eftimated. To a fecond portion of the water add 

 lime-water, till the whole of the magnefia and alumina be 

 feparated. From the weight of thefe earths the quantity of 

 their muriates may be eftimated, that portion of the mag- 

 nefia previoufly found to be in union with fulphuric acid 

 being dedufted. After this, remove the fulphuric acid by 

 barytes water, and the lime by carbonic acid, and the liquid 

 evaporated to drynefs will leave the common fait. 



6. Laftly : If the fixed mineral acids fliould alone be 

 found to exift in a water, it need fcarcely be obfervcd that 

 their quantities can be readily afcertained ; the fulphuric 

 acid by means of a barytic fait, and the muriatic acid by 

 means of a fait of filver. 



All thefe different precipitates fliould be dried uniformly, 

 or at leaft at fome known degree of temperature. It is not 

 eafy to fix this point, which muft in a great degree be regu- 

 lated by the nature of the fait, and the peculiar views of the 

 analyft ; fome choofing to reduce the falts to an anhydrous, 

 others to a cryftalhzed ftate. As a fort of check alfo to 

 the analyfis, it is proper to evaporate a known quantity of 

 the water to drynefs, in order to learn the grofs amount of 

 the faline matters it contains, which amount is to be com- 

 pared with the refults as obtained by the different proceffes 

 of the analyfis. 



Such are a few of the moft common methods recom- 

 mended for feparating and afcertaining the proportions of tlie 

 I o different 



