Scientific Intelligence — Geology. 175 



stated that he had discovered the presence of manganese in the water 

 of streams, lakes, &c., ahnost universally. He detected it in water 

 from the middle of Lake Superior, in Cochituate water, and in water 

 from various sources. It has usually been regarded as iron in pre- 

 vious analyses. He considered the observation as having an import- 

 ant 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 

 oxide of manganese in the blood. — Annual of Scientific Discovery, 

 p. 202. 



On the Presence of Organic Matter in Water, — The following 

 facts relative to the presence of organic matter in water were pre- 

 sented to the British Association, by Professor Forchhammer, as the 

 result of extended observations on the water, near Copenhagen. 



\st, The quantity of organic matter in water is greatest in sum- 

 mer. 2c?, It disappears, for the most part, as soon as the water 

 freezes. 3d, Its quantity is diminished by rain. 4tth, Its quan- 

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

 The hy permanganate of potash or soda is recommended by the Pro- 

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

 water. 



7. Arsenic in Chalybeate Springs. — Since the discovery of 

 afsenic in the deposits from certain chalybeate springs, it has been 

 asked whether the poisonous properties of this substance are not 

 neutralized by the state in which it is found. M. Lassaigne has 

 finished a series of experiments connected with this subject, for the 

 purpose of ascertaining the proportion of arsenic contained, in what 

 state of combination it exists, and the nature of the action which 

 these arseniferous deposits exert in the animal economy. The fol- 

 lowing are M. Lassaigne's conclusions : — 1. In the natural deposits 

 of the mineral waters of Wattviller, arsenic exists to the amount of 

 2*8 per cent. 2. A portion of these deposits, representing 1-76 

 grains of arsenic acid, or 1-14 grains of arsenic, produced no effect 

 upon the health of a dog. 3. This non-action shews that the poison- 

 ous property of the arsenic is destroyed by its combination with the 

 peroxide of iron, and thus confirms what has been before asserted, 

 that peroxide of iron, by combining with arsenuous and arsenic acid, 

 destroys their poisonous properties, and consequently becomes an 

 antidote for them. 



GEOLOGY. 



8. The Coal Formation of America. — The coal regions of America 

 are, from the explorations which have thus far been made, supposed to 

 be divided into three principal masses ; the great central tract, ex- 

 tending from Tuscaloosa, Alabama, to the west of Pennsylvania, and 

 being apparently continued to New Brunswick and Novia Scotia; 

 the second tract strikes north-westward from Kentucky, crosses the 

 Ohio, and stretches through Illinois to the Mississippi River ; a third 



