fi6 Historical Sketch of Improvements in [Aug. 



not far from the region of Mount Ararat. A small quantity of 

 the water from this Lake was sent by the late unfortunate travel- 

 ler Brown to Mr. Smithson Tennant. This portion was subjected 

 to analysis by Dr. Marcet. Its specific gravity was 1-16507 : 

 500 grs. of it being subjected to analysis yielded the following 

 saline contents : 



Common salt 85*00 



Muriate of magnesia 10*08 



Sulphate of soda 40*2& 



135*34 



The waters of this lake then contain more salt than any other 

 mineral water hitherto examined, except the waters of the Dead 

 Sea. (See Annals of Philosophi/, xiv. 150.) 



5. Dead Sea. — The waters which constitute this sea have a 

 greater specific gravity, and contain more salt than any other 

 mineral water hitherto examined. The specific gravity, as found 

 by different experimenters, varies a little. Thus 



Klaproth found it 1*245 



Gay-Lussac 1*2283 



Dr. Marcet 1*21 1 



I have lately drawn the attention of chemists to the discord- 

 ant analyses of this water by some of our most accurate chemists. 

 It affords a humiliating proof of the little progress that the ana- 

 lysis of waters has yet made, and the little confidence Avhich 

 can be put in the most accurate of our experimenters. It is, 

 therefore, of the utmost consequence that every one who pub- 

 lishes an analysis of a mineral water should record accurately 

 the successive steps of his analysis, and describe the mode which 

 he employed in calculating the respective proportions of each 

 constituent. Attention to this will render accurate experiments 

 always of value ; while those that merely give the results may 

 rest assured that their conclusions will be of no value hereafter 

 when the mode of analysis has become much more perfect than 

 it is at present. It will be worth while to give here again the 

 sahne contents extracted from 100 grs. of Dead Sea water by 

 |Claproth, Marcet, and Gay-Lussac. 



Marcet. Kiaproth. Gay-Lussac. 



Common salt 10*676 7*80 6*95 



Muriate of lime 3-792 10-60 3-98 



Muriate of magnesia. . 10*100 .... 24*20 .... 15*31 



Sulphate of lime .... 0-054 .... — .... — 



24-622 42-60 26-24 



Klaproth's salts were only dried at the temperature of boiling 

 water. This accounts for the much greater weight of his salts. 



