1821.] Mr, Smithson on some Capillary Metallic Tin. 271 



of the eye is dilated. This happened frequently to m^, and when 

 I tasted the salt of atropium, it occurred to such a degree that it 

 remained so for 12 hours, and the different degrees of light had 

 no influence. 



This is sufficient to show the poisonous effect of atropium. 



Article VI. 



On some Capillary Metallic Tin. By James Smithson, Esq. FRS. 

 (To the Editor of the Annals of Philosophy.) 



SIR, . Paris, Feb. 17, 1821. 



M. Ampere, a few days ago, accidentally in conversation, 

 mentioned a fact to me which much excited my attention, as it 

 appeared to me completely to confirm the explanation I had 

 ventured to offer of the mode of formation of the capillary cop- 

 per in the slag of the Hartz, printed in the Annals of Philosophy 

 for July, 1820. 



For some purpose of the arts, Mr. Clement formed a cylinder 

 of copper, and, to give it strength, introduced into it a hollow 

 cylinder, or tube, of cast iron. To complete the union of these 

 two cylinders some melted tin was run between them. With the 

 exact particulars of this construction, I am not acquainted, but 

 the material circumstance is, that during the cooling of this 

 heated mass, a portion of the melted tin was forced by the alte- 

 ration of volume of the cylinders through the substance of the 

 cast-iron cyhnder, and issued over its internal surface in the 

 state oi fibres, which were curled and twisted in various direc- 

 tions. This form in the fibres of copper I had considered as 

 very favourable to my hypothesis. Such was the tenuity of 

 these fibres of tin that little tufts of them applied to the flame 

 of a candle took fire, and burned like, cotton. 



This passage of melted tin through cast-iron has a perfect 

 agreement with the passage of water by pressure through gold, 

 and tends to elucidate and confirm the account of the celebrated 

 Florentine experiment. Had the water on that occasion issued 

 solid, it would have been in fibres. 



This penetration of solid matters by fluids, by means of great 

 mechanical force, will, perhaps, come to be thought deserving 

 of more attention than has been yet paid to it; besides any 

 scientific results to which the consideration of it may lead, it 

 may be found to afford compound substances, not otherwise 

 obtainable, and of value to the arts. 



I am, Sir, your mo&t obedient servant, 



; I James Smithson. 



