Mechanical Science, 397 



supports 480 pounds. This magnet is in the form of a horse-shoe, 

 and is composed of 9 plates ; its length is 17 inches, and its weight 

 43 pounds. 



I have myself seen (says the writer) this magnet carry the enor- 

 mous weight mentioned, and M. Keil says he can make them still 

 stronger, and competent to carry five times this weight, without 

 increasing their size in a greater proportion. He can also strengthen 

 old magnets, but never bring them near to those manufactured 

 upon the new plan. 



This discovery is said to be of great importance in the curative 

 art. The magnetio influence upon diseases has been supposed to 

 have been long known, and even cures affected in some cases by 

 making passages over the affected part by means of magnets. But 

 the bars used were too feeble ; and it appears that those belonging to 

 M. Keil which produce singular effects, are alone capable of demon- 

 strating the power of mineral magnetism over diseases. He has 

 succeeded in very violent rheumatic pains, epilepsy when not due to 

 organic lesions, cramp in the stomach, feebleness of sight, goitres, 

 head-ache, tooth-ache, tic douloureux, &c. The writer's brother 

 was a witness of one cure effected in a case of rheumatism. 



M. Keil also proposes to publish his investigations of terrestrial 

 magnetism, and the theory of magnetism, in which it is said he has 

 much new matter. He is on his way to Paris, so that we may hope 

 very soon to know the truth of the various matters stated, which, if 

 they have any reasonable foundation, cannot fail to be of great im- 

 portance. — Bull. Univ. A. xii. 241. 



9. Application of Magnetism to Medicine. — Dr. Becker has also 

 published a long account of effects produced by powerful magnets 

 on nervous and other patients. His conclusions are, that, i. Mine- 

 ral magnetism is a very efficacious agent in nervous pains, 

 especially when they are of long standing ; ii. That it is not of any 

 utility, but rather injurious, when inflammation or any other ex- 

 citation of the vascular system accompanies these pains ; iii. That 

 its effect is less sure on recent nervous cases, because they are 

 frequently accompanied by unperceived febrile affections. — Hufe- 

 lands Journal. 



10. Daily Magnetic Variation. — According to experiments made 

 by Humboldt, it appears that the daily variation is by no means the 

 same in different places. On January 29th, the variation at Berlin 

 was three times greater than on the 27th ; whereas, at Paris on the 

 29th, it was much less than that of the 27th at Berlin. At Berlin, 

 the variation, on the I lth of January, was twice that of the 10th at 

 Paris; that of the 10th was greater than that of the 11th. These 

 results do not appear to depend on any error of observation, but are 

 real consequences of local causes. By trials made at the mouth 

 and lowest part of the Freyburg mines, it was found that a depth 



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