35't Mr. Daniell on a iiew Register-Pijrometer, 



were perfectly brittle, breaking easily between the fingers. 

 The platinum bar also, which there was some difficulty in 

 removing from the cavity, presented a very extraordinary ap- 

 pearance. It was apparently embossed with crystal?, and was 

 evidently larger at the lower end than at the top : it was also 

 something contracted in length. Upon examination with n 

 lens no regular facets could be detected, but it had the appear- 

 ance of a bar constructed of plates of native platinum loosely 

 welded together. 



The register which contained the iron bar was considerably 

 bent, and had several transverse clefts in its substance, owing 

 possibly to its having become inclined in the crucible. Partial 

 fusion had taken place upon the surface of the bar, which had 

 run down and formed a knot at its lower extremity. About 

 an inch of the same end was found to have been converted 

 into steel, but all the rest retained the character of soft iron. 



Exp. 20. — 1 repeated the last experiment with the same 

 platinum bar in the register I. The arrangement was pre- 

 cisely the same, with the exception of the second register with 

 the iron bar, and the fire was maintained with equal intensity 

 for an equal time. 



The iron nails were found perfectly melted, and the porce- 

 lain superficially fused as before. The ring and wedge, how- 

 ever, were fixed in their places, and the index undisturbed, 

 but the measure was unfortunately lost from an accident. 

 The texture of the platinum ring was changed, as in the pre- 

 vious experiment, and the bar tightly fixed in the cavity. By 

 frequent gentle concussions it was removed without injury 

 to the black-lead, which had some slight marks of fusion upon 

 its surface, but was in a perfectly good condition. The bar 

 was in a still rougher state than before, highly crystalline, and 

 exhibited several large longitudinal clefts in its substance. It 

 was found, by measurement with callipers, to be 5^'ijth of an 

 inch larger in diameter at its lower than at its upper end, 

 and seemed to be approaching a state of complete disintegra- 

 tion. It was, however, perfectly hard and inflexible. My 

 intention was to have again exposed it for several hours to 

 the same degree of heat, with the expectation that the disin- 

 tegration would have been complete, and that it would actually 

 have fallen in pieces during the operation : in the mean time 

 I chanced to make it red hot upon a common charcoal fire ; 

 and upon attempting to lay hold of it with a pair of tongs the 

 two ends dropped oft", and I only withdrew the small portion 

 which I had grasped, and which was flattened and fractured 

 by even this slight compression. The two ends were after- 

 wards carefully, but with difficulty, raised from the fire, and 



when 



