38 Mr. Ritchie on a Torsion Galvanometer. 



at the distance of several hundred feet, and consequently a 

 battery of moderate power would act on needles at the distance 

 of a milej and a battery of ten times the power would deflect 

 needles with the same force, at the distance of a hundred miles, 

 and one of twenty times the force, at the distance of four hun- 

 dred miles, provided the law we have established for distances 

 of seventy or eighty feet hold equally with all distances what- 

 ever. 



PRACTICAL AND PHILOSOPHICAL OBSERVATIONS ON 

 NATURAL WATERS. 



BY WILLIAM WEST, ESQ. 



1. On the Water from Peat Lands, and its application to 

 domestic purposes. 



T HAD an opportunity, some time since, of closely examining 

 many specimens of water from this part of the country, 

 (Leeds,) which were soft and nearly pure, containing from 

 half a grain to two grains of solid matter in the gallon, one 

 part in 50 or 60,000, but tinged by colouring matter from 

 peat. With most of the re-agents no action took place, or it 

 was so slight as to be difficult of detection ; but when evapo- 

 rated until a gallon was reduced to a few spoonfuls, the com- 

 position of this small portion was easily shewn to be sufficiently 

 complicated : and it varied greatly in different specimens which, 

 passing in their original state under the action of the tests with- 

 out any alteration being produced, might have been supposed 

 exactly similar. The fact is, the water precipitated from the 

 rain and mountain mists had taken up small portions of the 

 soluble substances which came in its way ; but its course had 

 been too short, and its action too much confined to the earth's 

 surface, to acquire much from any of these. These streams 

 were on high moor land; either running in the ravines, or 

 springing from natural or artificial openings in mill-stone 

 grit. 



One practical difficulty of considerable importance arises 

 when water from brooks in such situations is employed, or 



