202 ANNUAL OF SCIENTIFIC DISCOVERY. 



situations. He suggests the propriety of further inquiry upon this sub- 

 ject, as the results may be important in connection with steam-naviga- 

 tion, the injurious incrustation, which is liable to form in boilers at sea, 

 being composed chiefly of this substance. Brewster's Magazine, Sept. 



ON THE. EXISTENCE OF MANGANESE IN WATER. 



AT a meeting of the American Academy, in January 1849, Dr. 

 Charles T. Jackson stated that he had discovered the presence of man- 

 ganese in the water of streams, lakes, &c., almost universally. He 

 had detected it in water from the middle of Lake Superior, in Cochit- 

 uate water, and in water from various sources. It has usually been 

 regarded as iron in previous analyses. He considered the observation 

 as having an important bearing in accounting for the deposits of bog 

 manganese at the outlets of ponds, lakes, and in bogs, as well as for 

 the source of the oxid of manganese in the blood. 



o 



ON THE PRESENCE OF ORGANIC MATTER IN WATER. 



THE following facts relative to the presence of organic matter in 

 water were presented to the British Association, by Professor Forch- 

 harnmer, as the result of extended observations on the waters near 

 Copenhagen. 1st. The quantity of organic matter in water is great- 

 est in summer. 2d. It disappears for the most part, as soon as the 

 water freezes. 3d. Its quantity is diminished by rain. 4th. Its quan- 

 tity is diminished if the water has to run a long way in open channels. 

 The hypermanganate of potash or soda is recommended by the Pro- 

 fessor as a most excellent test for the presence of organic matter in 

 water. Atherxeum, Sept. 22. 



PROBABLE CAUSE OF GOITRE AND CRETINISM. 



M. GRANGE has sent to the Paris Academy of Sciences a paper 

 containing the results of numerous analyses of waters from the talcose, 

 anthraxiferous, and cretaceous formations of the valley of Isere, in 

 Switzerland. The investigations were made at the suggestion of M. 

 Dumas, the celebrated French chemist, with a view of ascertaining 

 the relative quantities of chlorides, sulphates, and carbonates con- 

 tained in the waters from the glaciers down to the plains, and of 

 comparing together the salts dissolved in the waters of the different 

 formations. The locality, as has been stated, was the mountains in 

 the valley of Isere, some of which attain the height of 3,000 metres.* 

 The investigation shows, 1st, That the quantity of dissolved salts 

 increases from the summit of the mountains towards the plain. 2d. 

 That in the talcose and anthraxiferous formations the chlorides of sodi- 

 um and magnesium, and the sulphates of soda, lime, magnesia, and po- 

 tassa, diminished relatively to the total mass of salts as we descend 

 from the summits, and form 25 to 30 per cent, of the dissolved salts ; the 

 sulphates forming from 24 to 31 per cent., and the carbonates from 36 

 to 47 per cent. 3d. That in the anthraxiferous formations the sul- 



* A metre equals 39.37 inches. 



