408 
SUMMARY OF CURRENT RESEARCHES, ETC. 
(6) Miscellaneous. 
Drawing imperfectly visible Details with Camera lucida.* — Dr. 
J. "W. Chr. Goetliart uses red-tinted paper for drawing with the camera 
lucida, and thus obviates the inconvenience arising from the glare of the 
paper which, under high powers especially, often renders the picture or its 
details difficult to be seen. One volume of a saturated alcoholic solu- 
tion of fuchsin is mixed with two or three volumes of 96 per cent, spirit, 
and the sheets of drawing-paper are immersed in the solution for a few 
seconds. The paper is then hung up by one corner to dry. After 
drawing the paper may be decolorized by immersing it in 1-2 per cent, 
solution of nitrite of potash or soda, to which, while the dish is being 
moved to and fro, a small quantity of sulphuric acid is gradually added. 
At a temperature of 40-50° decoloration rapidly ensues, while at room- 
temperature it is rather slow. As soon as the paper assumes a light 
yellow tone it is to be carefully washed in clean water, and then dried. 
The point of the lead pencil should be painted white. 
* Nederlandsch Kruidkundig Archief, vi. (1892) pp. 161-5. See Zeitschr. f. 
wise. Mikr., x. (1893) p. 467. 
