On the Origin and Practice of Lithographj . 217 



art of multiplying originals ; engraving, as that of multiplying 

 copies. 



The facts on which the lithographic art is founded are the re- 

 sult of affinities simple enough, but the applications of which 

 have not been observed. 



1st. It is a fact that a line drawn with a crayon, or an oily ink, 

 upon stone of a calcareous nature, adheres to it so strongly, that 

 it can only be taken off by meciianical means. 



2dly. All the parts of the stone not covered with the oily mat- 

 ter will receive, retain, and absorb water. 



Sdly. Suppose, then, that any combination of lines has been 

 drawn upon the stone, and that it has afterwards been thus 

 treated with water, — if a coating of oily and colouring matter be 

 next applied to the stone (as in letter-press printing), it will 

 only attach itself to the lines formed by the oily ink, and will be 

 rejected by the moistened parts. 



The hthographic process, in short, depends on this : that the 

 stone, moistened with water, rejects the ink ; and when oiled, 

 that it rejects the water and retains the ink : so that in applying 

 and pressing a leaf of paper upon the stone, the oily, resinous, 

 and coloured lines will alone be transferred to it, presenting the 

 counter-impression of what is represented on the stone. 



The design, instead of being traced in reverse upon the stone, 

 may be drawn with prepared ink, on paper, and thence trans- 

 ferred to the stone ; by wbich means the stone will then return 

 the exact image of the original. 



All stones will do for the purpose, which are susceptible of be- 

 ing penetrated by any oily substance, and of imbibing water with 

 facility ; provided they are compact, of a clear and uniform co- 

 lour, and capable of receiving a fine polish. The whole of these 

 qualities are very iiappily combined in certain calcareous stones, 

 which are found in the quarries of Solen Hofen, near Pappenheim 

 in Bavaria, and may be met with, it is believed, in several other 

 places. They consist of almost pure carbonate of lime. 



When the stone is dressed and polished, the artist may, with- 

 out any other preparation, sketch his design upon it, either with 

 cravon, pen, or pencil. The grain of the stone being more fine 

 and equal than that of the finest and best pressed vellum, he will 

 find himself enabled to draw his lines with so much the greater 

 equality, firmness, and delicacy. 



The mode of taking off the impressions from the stone is that 

 part of the process which, it is to be regretted, is still kept in 

 some degree of mystery, or rather, it should be said, which has 

 not been communicated ; for it is difficult to imagine that there 

 can be much mystery to any scientific artist in an operation 

 yvhich is so well understood, and has already been carried to 



such 



