©N DRAWINGS OF FLOWERS, &C. 267 



and, the.paper being immersed, the application of the solution to 

 every part should be insured by the use of a sponge. The paper 

 is then to be removed, drained of its superfluous moisture, and 

 nearly dried by pressure between folds of linen or bibulous 

 paper. 



Two hundred and forty grains of fused nitrate of silver are then 

 to be dissolved in twelve fluid ounces of water, and this solution 

 is to be applied by means of a sponge to one side of each sheet of 

 the previously prepared paper, which side should be marked with 

 a pencil, so that when the paper is fit for use the prepared side 

 may be distinguished. The sheets of paper are then to be hung 

 upon lines in a dark room to dry, and when nearly free from 

 moisture, their marked sides are to be once more sponged over 

 with the solution of silver, and finally dried ; they are then to be 

 cut into pieces of convenientsize, and preserved from light, or even 

 too much exposure to air, by being wrapped up in several folds of 

 brown paper, and kept in a portfolio. 



The proportions above recommended are sufficient for the pre- 

 paration of a quire of the kind of paper alluded to ; if more of 

 the salt of silver were used, the paper would indeed become dark- 

 er by the action of light, but its expense would be proportionally 

 increased; and when prepared in the manner directed, it assumes 

 by less than a minute's exposure to the rays of the sun, a rich 

 mulberry brown tint, of sufficient intensity to define an outline 

 very beautifully, which indeed is all that is required. 



To use this paper, the specimen, of which a drawing is required, 

 is removed from the herbarium, placed on a piece of the paper, 

 and kept in situ by a pane of common glass pressed by weights; a 

 piece of plate glass, however, is preferable, as it is sufficiently 

 heavy to press the plant close to the paper. The whole is then 

 placed in the sunshine, and in less than a minute all the uncover- 

 ed parts of the paper will assume a rich brown tint. The paper 

 should then be removed from the direct influence of the sun, and 

 placed in a book until the drawing be made permanent : the spe- 

 cimen, quite uninjured by the process, may then be replaced in 

 the herbarium, and the drawing of another taken, and so on. So 

 rapidly is this process executed, that twenty- five or thirty draw- 

 ings may be obtained in an hour, providing we are favoured with 

 a direct sunbeam; if, however, we have only the diffused day-light 

 five or ten minutes, and sometimes even more, are required to 

 produce a drawing with well defined outlines. 



