1855.] on Nature-Printing, 117 



able by this means to blend one colour into another, but to print all 

 the colours at one single impression. 



T\\e first practical application of Nature-Printing for illustrating 

 a botanical work, and which has been attended with considerable 

 success, is Chevalier Von Ileufler's work, on the Mosses,* collected 

 from the Valley of Arpasch, in Transylvania ; the second, {the first 

 in this country,) is the " Ferns of Great Britain and Ireland," in 

 course of publication, under the editorship of Dr. Lindley, and 

 printed by Messrs. Bradbury and Evans. Ferns, by their peculiar 

 structure and general flatness, are especially adapted to develope 

 the capabilities of the process, and there is no race of plants where 

 minute accuracy in delineation is of more vital importance than 

 the Ferns ; in the distinction of which, the form of indentations, 

 general outline, the exact manner in which repeated subdivision is 

 effected, and most especially the distribution of veins scarcely 

 visible to the naked eye, play the most important part. To express 

 such facts with the necessary accuracy, the art of a Talbot or a 

 Daguerre would have been insufficient until Nature-Printing was 

 brought to its present state of perfection. 



Mr. Bradbury then adverted to the ingenious and beautiful 

 productions of Felix Abate, of Naples. His Nature-representations 

 consist of sections of wood, in which the grain is admirably repre- 

 sented. He terms his peculiar process Thermography, or the Art 

 of Printing by Heat. The process consists in wetting slightly the 

 surface of the wood of which facsimiles are to be made, with any 

 diluted acid or alkali, and then taking an impression upon paper, 

 or calico, or white wood ; the impression is quite invisible, but by 

 exposing it for a few instants to a strong heat, the impression appears 

 in a more or less deep tone, according to the strength of the acid or 

 alkali. In this way every gradation of brown from maple to 

 walnut is produced ; but for some woods which have a peculiar 

 colour, the paper, &c. is to be coloured, either before or after the 

 impression, according to the lightest shades of the wood. Abate, 

 in his manipulations, also employs the ordinary dyeing process. 



It is to be hoped that Abate's process may become alike useful to 

 the natural sciences and the decorative arts. 



Mr. Bradbury stated, in conclusion, that we are indebted to — 



Kniphof, for the application of the process in its rude state ; 



Kyhl, for having first made use of steel-rollers ; 



Branson, for the suggestion of the electrotype ; 



Leydolt for the remarkable results he obtained in the repre- 

 sentation of flat objects of mineralogy, such as agates, fossils, 

 and petrifactions ; 



* Specimen Florce Crijptogamcc vallis Arpasch Carpatoe Transylvani ; Con- 

 scripsit Ludovicus Elques de Heufler. Vienna, 1853. Imp. folio. 



