Farther Observations on Experiments, fyc. 257 



he ceased to move. He experienced in his breast a sensation 

 similar to that which precedes emophtisie, a disease to which he 

 had been subject in his youth. He did not spit blood, however, 

 on the summit of Mont Blanc. One of the guides having acci- 

 dentally received a stroke in the nose, lost a little blood, 

 which appeared of a much blacker colour than usual. Dr 

 Clark, as well as Captain Sherwill, had a severe headache, 

 and their faces were pale and contracted. The Captain 

 described a singular sensation which he experienced near the 

 summit. He felt as if his body possessed an extraordinary 

 degree of elasticity and lightness, and as if his feet scarcely 

 touched the ground. The guides were in general very much 

 fatigued, and complained of headaches. Our travellers return- 

 ed to the Grands Mulets, where they slept, and next morning 

 they returned in safety to the valley. — Bibl. Univers. No- 

 vember 1825, p. 245. 



Art. XII. — Farther Observations on the History of Mr Bab- 

 bage"s Experiments on the Production of Magnetism by Ro. 

 tation. 



In the last number of this Journal we laid before our read- 

 ers a popular summary of the remarkable discoveries which 

 have been recently made in this country and in France, on the 

 production of magnetism by rotation. One of the objects of 

 this paper was to assign to each philosopher concerned, the 

 share which he had in these discoveries, and we had the good 

 fortune to receive from a distinguished correspondent an 

 interesting communication on that subject, which formed 

 the ground-work of our popular summary. We regret, how- 

 ever, to find that our information was not so minute as could 

 have been wished, and that the opinions and experiments of 

 Mr Babbage were not so amply detailed as their importance 

 demands. We hasten, therefore, to supply this defect, which 

 neither we nor our correspondent had before the means of 

 avoiding. 



About the month of November 1824, Mr Barlow's experi- 

 ment, in which he produced a deviation of the magnetic 



VOL. IV. NO. II. APRIL 1826. it 



