74 On the Cutting of Steel by Soft Iron. 



of the best methods of evolving heat by mechanical impulse. 

 The steel of course loses its temper at the place of section, 

 and there only; for the softening extends but a little way, and 

 is limited to a narrow portion, marked by the iris colours 

 known to be produced by heat upon steel. 



The iron plate, as Mr. Daggett states, becomes only warm, 

 and wears away, only very slowly; yet it does wear, for 

 the edges are left rough, and the channel of section in the 

 steel exhibits with a magnifier minute striae or grooves, run- 

 ning in the direction of the wheel's revolution. I know not 

 that there is any reason to suppose any peculiar electrical 

 phenomenon, except that electricity always accompanies heat. 

 It is plain from the important use made of this mode of cutting 

 steel by the Shakers and by Mr. Barnes, that it may be of 

 considerable practical importance. 



As a philosophical experiment it is highly interesting : and 

 it remains yet to be shown, why the heat evolved by the im- 

 pulse should nearly all be concentrated in the steel, and be 

 scarcely perceptible in the iron : neither is it perfectly clear 

 that even ignited steel should be so easily cut by the im- 

 pinging of soft iron. No smith probably ever thought of at- 

 tempting to divide steel by applying an iron tool. — Silliman's 

 Journal, vol. vii. p. 342. 



Besults of the Analysis of the principal Brine Spritigs in the 

 State of New York. By Mr. G. Chilton. 



Process. 



1. The water of each bottle, after weighing it and taking 

 its specific gravity*, was slowly evaporated to dryness in a 

 glass basin. 



2. The deliquescent salts were extracted from the dry re- 

 siduum by digestion in alcohol, and separated from each other 

 by converting them into sulphates in the usual way. 



3. The mass, after the separation of the deliquescent salts, 

 was dissolved in water and filtered. The carbonate and sul- 

 phate of lime left on the filter were separated by muriatic 

 acid, &c. 



4. The filtered solution was treated with carbonate of soda, 

 boiled, and filtered ; the carbonate of lime left on the filter 

 indicating the quantity of sulphate of lime decomposed. 



5. To the last clear solution, neutralized by the addition of 



* The water from the deep well at Montezuma was neglected in respect 

 to its specific gravity. One or two of the samples had the odour of sulphu- 

 retted hydrogen, which was not regarded in the examination, in conse- 

 quence of the bottles being imperfectly corked : I think they were those 

 from Montezuma. 



muriatic 



