268 ON DRAWINGS OF FLOWERS, &C. 



If drawings of recent plants be required, specimens of proper 

 size should be cut, and if not too rigid, placed on a piece of paper, 

 and kept in a proper position by means of a pane of glass, as in 

 the case of dried specimens ; but if the plant be rigid, the speci- 

 mens should be placed for twenty-four hours between folds of 

 blotting paper, under a heavy weight, before placing them on the 

 sensitive paper. Having obtained as many drawings as are re- 

 quired, the next thing is to fix them, so that their otherwise 

 evanescent character may not deprive them of their value. For 

 this purpose place them in a dish, and pour cold water over them ; 

 allow them to soak for ten minutes, and then transfer them to, or 

 sponge them over with, a solution, made by dissolving an ounce 

 of common salt in half a pint of water, to which half a fluid ounce 

 of the tincture of sesqui-chloride of iron has been added. The 

 drawings thus prepared may be dried by pressure between folds 

 of linen, and exposure to the air; and may then be examined 

 without danger. On looking at them, every one must be struck 

 with the extreme accuracy with which every scale, nay, every 

 projecting hair, is preserved on the paper ; the character and ha- 

 bit of the plant is most beautifully delineated, and if the leaves be 

 not too opaque, the venation is most exquisitely represented; this 

 is particularly the case with the more delicate ferns, as Polypodium 

 Dryopteris. Among those classes of plants which appear to be 

 more fitted than others for representation by this process, may be 

 ranked the ferns, grasses, and umbeliferous plants ; the photoge- 

 nic drawings of the former are indeed of exquisite beauty. 



The fact of the object being white on a brown ground does not 

 affect the utility of this mode of making botanic drawings ; indeed 

 I almost fancy that their character is better preserved by this con- 

 trast to tint, than by a coloured outline on a white ground. Every 

 one will be fully aware of the value of this process to the botanist, 

 in obtaining drawings of rare plants preserved in the herbaria of 

 others, and which he would otherwise have probably no means of 

 obtaining. 



If the drawing of a tree or a large shrub be required, a box 

 blackened inside, having a hole at one end about one and a quarter 

 inch in diameter, must be provided ; in this hole should be placed 

 a lens of five or six inches focus ; if one of longer focus be used, 

 the dispersion of light becomes too great to insure an accurate 

 representation. When the tree or shrub is well illuminated by the 

 solar beams, the lens should be presented towards it, at a distance 



