65:2 Intelligence and Miscellaneous Articles. 



form of force, or rather becomes a current of electricity, acting in op- 

 position to the primary current by which the magnetism is induced. 



From an examination of all these results, Mr. Hunt is disposed 

 to regard electro-magnietlc power as impracticable, on account of its 

 cost, which must necessarily be, he conceives, under the best con- 

 ditions, 50 times more expensive than steam power. 



The chairman agreed with Mr. Hunt in his conclusion of the im- 

 probability of any result being obtained from electro-magnetism 

 which could enable it to compete with steam as a motive power. 

 At any rate, the point to which the attention of engineers and ex- 

 perimentalists should be turned at present was, not the contriving 

 of perfect machines for applying electro- magnetic power, but the 

 discovery of the most effectual means of disengaging the power 

 itself from the conditions in which it existed stored up in nature. 

 Mr. Faraday assured us that in a single drop of water is contained 

 as much electricity as is developed in a thunder-storm. The portion 

 of this which we can liberate by any existing battery is very small, 

 so small, that, as shown by Mr. Hunt's paper, its practical use 

 cannot be profitable. The study of electro-chemistry, he thought, 

 was a more promising field, and one from which might at a future 

 time be developed a power which should supersede even steam. 



FIBROUS HYDKATE OF MAGNESIA, NEMALITE OF NUTTALL, 

 THOMSON AND CONNELL. 



The fibrous hydrate of magnesia, which was first discovered and 

 named by Nuttall without analysis, but which was considered by 

 him as hydrate of magnesia, has been twice subjected to analysis 

 with very discordant results. Thomson, having examined a speci- 

 men which contained a portion of silica, or silicate of magnesia, 

 mechanically intermixed, gave for this mineral the formula 



MgO,Si03 + 2MgO,HO, 



his analysis having given him about 12 per cent, of siKca. Connell 

 has more recently analysed the same mineral, and, happening to 

 have a specimen which contained no silica, but a considerable quan- 

 tity of carbonate of magnesia, also mechanically intermixed, he gives 

 as the result of his analysis the formula 



5MgO,HO -f MgO,C02 -t- HO, 



a highly improbable one. 



Mr. "Whitney has examined a specimen of this mineral from the ca- 

 binet of F. Alger, Esq., and finds that when perfectly pure it contains 

 neither silica nor carbonic acid, but that it is a fibrous hydrate of mag- 

 nesia, though it often occurs mixed with the silicate and carbonate 

 of magnesia. If a few fine fibres of the mineral be placed in dilute 

 acid, the effervescence will be found to be but momentary, and con- 

 fined to the extremities of the fibres, where they were in contact 



