on the Continent. 173 



four feet long are thus prepared without much trouble or expense, 

 and they may be made double the size. The blocks sometimes 

 taken from the quarries have a superficies of ten feet square. The 

 enamelled surface of this lava is not even, like the enamel of porce- 

 lain ; but it is a little grained, which renders it particularly adapted 

 for pictures on a large scale, as historical pictures, &c. If it were 

 required to use this substance for miniature painting, the layer of 

 enamel must be perfectly smooth ; and though this would be diffi- 

 cult to effect, the reporter is of opinion that it would not be impos- 

 sible. The Count de Chabrol, when prefect of the Seine, first 

 employed this lava for the trottoirs, or foot-pavements, of the streets ; 

 arid M. Mortelique, being induced from its fusibility, its vitreous 

 qualities, and its porous consistence, to suppose that it was suscep- 

 tible of being enamelled, made a variety of experiments, and ulti- 

 mately, in 1827, exhibited a head, painted the natural size, on a 

 plate of this lava, which was considered worthy of a prize. But in 

 order to render this generally useful, it was requisite to make the 

 enamel painting so nearly analogous to oil painting, that historical 

 painters might acquire the art without material loss of time. The 

 great difference was that, on the enamel, as on porcelain, the colour 

 could only be applied by small touches in juxtaposition, and could 

 only be degraded by letting the white ground appear more or less 

 through the transparent tints. This mode of proceeding, which is 

 that of miniature painters, is much too tedious for artists accustomed 

 to lay the colour thickly on the canvass. M. Montelique has there- 

 fore applied himself to the discovery of a white which will combine 

 itself with all the colours used in enamel painting, without decom- 

 posing them. In this he has fully succeeded, and by this discovery 

 has removed the only difficulty existing in the use of the lava for 

 paintings; so that pictures of the largest size may now be painted 

 in enamel with the same facility as in oil ; and with every facility of 

 retouching the picture, when in progress, is combined the advantage 

 of the colours being rendered capable of bidding defiance to the 

 ravages of time, by the unlimited manner in which they may be 

 passed through the fire. Had this discovery been made three cen- 

 turies earlier, we should not have to deplore the deterioration of the 

 * Last Supper' of Leonardo da Vinci, and the ' Descent from the 

 Cross' of Daniel di Volterra. 



SOCIETE DE GEOGRAPHIE DE PARIS. 



Annual Prize. This prize was proposed for the most important 

 geographical discovery made during the year 1829. The committee, 

 in their report, first mentioned, in terms of praise, Captain King's 

 attempt to explore part of Patagonia, but added, that as his voyage 

 has not yet been published, no judgment can be formed of the impor- 

 tance of the results at which he has arrived. M. Parchappe, by his 

 discoveries in South America, has thrown new light on the course 

 of the Uraguay, and other rivers of the basin of Parana. This 

 traveller, in the twelve years which he has passed in the province of 



