186 ANNUAL OF SCIENTIFIC DISCOVERY. 



STEREO-CHROMIE ; A NEW MODE OF FRESCO-PAINTING. 



A NEW mode of fresco-painting has been introduced in Germany, 

 which appears quite likely to supersede the old method, and to yield 

 remarkable advantages ; in fact, to render such painting perfectly invul- 

 nerable to the effects of climate. The discoverer is Prof, von Euchs, 

 of Munich, who has had to undergo all the opposition and jealousies 

 incident to discoverers in general. Though now, in his old age, his 

 invention is made use of in the new frescoes at Berlin, it is possible 

 that he may die without reaping any personal benefit from it. 



Stereo-chromie is, in fact, a preserver of the wall on which it is 

 painted. By the chemical action of the solution sprinkled over the 

 picture, whilst in progress, the whole ground on which it is painted and 

 the picture itself becomes one hard, flinty mass, and the very colors are 

 converted into the hardest stone. So hard, indeed, is it, that neither 

 fire nor damp has the slightest effect on it. In the specimens exhibited, 

 the pictures are upon pieces of wainscot covered with mortar, and the 

 wall on which a stereo-chromie fresco is to be executed undergoes a 

 certain preparation. Then the colors are not combined, as in alfresco, 

 with lime, but with a solution of silex ; and all the advantages of fresco 

 painting are obtained without any of its disadvantages. This species 

 of painting resists every influence of climate, and may be confidently 

 used as an external coating for buildings in any part of the world. 

 To the artist himself it offers the most important recommendations. He 

 is not confined to time in executing it. He can leave off when he 

 pleases, and for any length of time, which he cannot do in fresco work 

 by any means, nor in oil-painting within certain limits. The highest 

 advantage of all, however, is, that the same part may be painted over 

 and over, as often as you please, which is not possible in fresco ; and, 

 consequently, in this new mode the most perfect harmony may be pre- 

 served throughout the largest possible painting. In fresco, the artist 

 is the slave of his materials ; here , he is their arbitrary master to the 

 fullest extent. London Athen&um. 



ON WORKING AND MODELLING IN PLASTIC IVORY. 



MADAME ROUVIER'S process is as follows : Take the waste turn- 

 ings of ivory, bone, horn, &c., and steep them in a vessel containing a 

 weak acid solution. Nearly all the acids will do for this purpose, but 

 the following are preferable muriatic, nitric, tartaric, acetic, citric, 

 and oxalic ; also phosphate of lime. The solution is placed in a 

 water bath, at a temperature of 35 to 40 C., (95 to 140 Fall.,) in 

 order to obtain complete liquefaction. It is then passed through fine 

 muslin, and about one fourth of the quantity of ivory gelatine is next 

 added to absorb the solvent. When the paste is well prepared, the 

 excess of liquid, and any foreign gases, are removed by means of an 

 air-pump ; it thus becomes homogeneous, membranous, and very close. 

 In this state it would be difficult to run it for use ; for this purpose, it 

 must be dissolved in copal or lac varnish, and, in this state, it may be,.. 

 run into moulds. When tho paste is in the moulds, it may be made to 



