164 Miscellaneous Intelligence. 



O" 



the same countries and at the same period. 3. That the finer sort 

 of these vases are superior in regard to the preparation of the 

 clay, and the elegance and variety of the forms, as well as the care 

 of the paintings, to all others of the kind, whether of Roman or 

 of modern manufacture, insomuch that the pottery of the most 

 remote ages forms the model of that of the present times. 4. That 

 the art of manufacturing these vases, as practised in very remote 

 times, is much more worthy of estimation than our best perform- 

 ances in that way, since the ancients were not in possession of 

 many assistances which are applied to the art by us ; and because 

 some things which are now done without difficulty, by means of 

 certain instruments or machinery, were, in those times, perfected 

 by means of the hand alone, by the greater dexterity of the artists. 

 5. That certain circumstances were peculiar to the very ancient 

 arts of making and ornamenting those earthen vessels which have 

 evidently been lost in later times, of which may be mentioned in 

 particular the composition of a very thin varnish, which gave a 

 heightening to the colour of the clay in a greater or less degree, 

 and afforded a very thin firm black coating, retaining its lustre to 

 the most remote ages, and capable of resisting the action of acids 

 and other fluids ; so that the modern art of manufacturing pottery 

 ware may be materially improved, not only with regard to the 

 forms and ornaments, but also the preparation and application of 

 the materials, by a diligent and continued examination of those 

 very ancient vases. — Edin. Phil. Journ. xiii. 62. 



5. On the Repulsion exerted by Heated Bodies at sensible Distances. 

 By M. A. Fresnel. — M. Libri published last year, in an Italian 

 Journal, some curious experiments on the motions of a drop of 

 fluid suspended on a metallic wire, of which one extremity was 

 heated : he observed that the drop always receded from the source 

 of heat, even when a very sensible inclination was given to the 

 wire. This phenomenon may be explained by the changes in the 

 capillary action of the solid surface and the liquid, caused by the 

 elevation of temperature, and which will be different at the un- 

 equally heated extremities of the drop. It may also be admitted 

 (which is the same thing) that the molecules repel each other more 

 powerfully as their temperature is higher. According to this hypo- 

 thesis, each liquid molecule in contact with the metallic wire will 

 be more repelled by the small portion of surface on the side to- 

 wards the source of heat, than by the contiguous portions, from 

 which would result a sum of many small actions, all tending to 

 impel the drop from the heated extremity. 



In neither of these methods of viewing the phenomenon is it 

 necessary to suppose that the reciprocal action of the molecules 

 extends to sensible distances ; but some other experiments of M. 

 Libri on the same subject appears, as hs has observed, to indicate 



