284 SUMMAKY OF CUKRENT RESEARCHES RELATING TO 



Conversazione of tlie Society (Vol, II. (1882) p. 444). Mr. Draper has 

 during the last year published several articles on the subject (giving 

 hints from practical experience of the best methods of procedure), 

 which, in the main, are not susceptible of abstract, but from which we 

 take the following : — 



The effect of a microscopical painting is greatly enhanced by its 

 being drawn within a circle surrounded by a black margin forming a 

 square. A circle 3| inches gives the best effect and approaches nearest 

 the impression made upon the mind by a field with a B eye piece. A 

 brass gauge should be kept for marking the circle and square. 



The Wollaston camera lucida is to be preferred. The neutral 

 tint reflector reverses the image, which renders it more difficult to fill 

 in the drawing afterwards. 



No drawings can be greatly advanced by the camera lucida. The 

 latter can be used for quickly and accurately fixing and drawing the 

 salient points, but any attempt at elaborate detail will end in confusion, 

 and useful as it is in the earliest steps, it should be discarded as soon 

 as possible. 



The colours should be dry cakes. Moist colours in tins soon 

 become contaminated. Everything should be of the first quality — the 

 Indian-ink of superlative excellence. " All the colours should be 

 prepared, and the tints mixed (to use the words of Opie) with brains." 



In a later article the author " appends an experience of some im- 

 portance. 



An object for drawing should be magnified to show all the parts 

 necessary for its elucidation, in fact, to understand it as a whole ; and, 

 as a rule, it should occupy the entire field of vision. It sometimes, 

 however, happens that many elongated preparations, as for instance, 

 the tongue and appendages of a bee, or a double-stained section of a 

 botanical specimen, cannot without reducing the magnifying power to 

 a useless attenuation be included in a circle, as recommended in a 

 former paper, except at the loss of considerable and important detail ; 

 in such cases the circle must be abandoned and the drawing made in 

 parts, by shifting the position of the object until the whole is com- 

 bined on the paper. This is attended with some difficulty in the 

 management of the camera lucida, but can be overcome in the follow- 

 ing manner : — Having an elongated object, which cannot be seen in 

 its entirety in one field of view, the process is, to draw the outline and 

 salient positions of one end, or half-making two prominent points on 

 the paper corresponding with two places in the subject ; these positions 

 are easily remembered. The object is then moved by tl:e stage 

 adjustments, upwards or downwards, as the case may be, until the 

 other portion is in the field. The marked points are coincided, by 

 shifting the drawing block, and the remainder of the outlines 

 finished ; the minute details of the drawing, and painting, afterwards 

 continued from the object itself. By this method, the camera lucida 

 may be used without difficulty with four combined fields of vision, 

 and the various parts of the object so fitted as to result in a 

 drawing of considerable dimensions, perfectly true in its contours. 

 Botanical sections and elongated parts of insects, under fairly high 



