74 



HARDWICKE'S SCIENCE-GOSSIP. 



Malvern. Arthur D. Melvin, RIadresfield. Botany 



(Phanerogams). 

 Malvern Link. Richard F. Towndrow. Botany 



(Phanerogams), Entomology. 

 Worcester. Harold F. Bibbs, 25 Tything. Botany 



(Phanerogams). 



Yorkshire. 



Sheffield. James E. Westby, S3 Barber Road. 

 Geology (Local and Getter ai). 



York. Robert Dutton, 6 Lowther Street, The 

 Groves. Entomology, 



York. Arthur Angell, 35 Orchard Street. Ento- 

 mology. 



Ireland. 



Lurgan, co. Armagh. Rev. Henry W. Lett, M.A, 

 Ardmore Glebe. Botany (Phanerogams). 



Jersey. 

 Bagot. J. Sinel. Crnstacea, Mollnsca, also General 

 Natural History. 



Sweden. 

 Askersund. Alfred Beckman. Botany (Phanerogams 

 and Lichens of Sweden). 



ON DRAWING AND PAINTING FROM THE 

 MICROSCOPE. 



MR. EDWIN HOLMES in the February number 

 referring to my paper on the above subject, 

 states I omitted to notice that outlines produced by 

 the camera lucida " are reversed, which would intro- 

 duce a difficulty in filling up from the microscope." 

 This observation is most opportune, as it reveals the 

 possibility that many a young aspirant with a taste 

 for drawing by the aid of a lucida has been in some 

 degree working in the dark, puzzled by his inability 

 to overcome this imperfection of "reversion," and 

 frustrated in continuing his drawing, under direct 

 vision through the microscope. 



The remark of Mr. Holmes leads me to infer, that 

 he has worked only with the form of camera lucida, 

 known as the neutral tint reflector — an instrument 

 essentially useful, capable of being handled with 

 dexterity, it does not fatigue the eye, and the field 

 of view is easy to distinguish on the paper ; but it 

 has the great disadvantage that everything is re- 

 versed, consequently, when removed, any further 

 drawing from the microscope is extremely difficult, 

 not to say, impossible. 



This reflector (a square of thin microscopical glass 

 will answer the purpose) is placed in a suitable 

 fitting in front of the eye-piece at an angle of 45°, 

 the microscope being horizontal. Looking through the 

 arrangement, the eye receives the image reflected on 

 the surface of the glass, at the same time seeing the 

 paper and pencil on the table beneath, having only 

 one reflection, necessarily the top of the object is at 



the bottom of the paper, the bottom at the top, a 

 confusion which impedes, except by an experienced 

 hand, any further progress. The apparatus is there- 

 fore only useful for mere outline, rapid sketching, or 

 making memoranda. I am persuaded this neutral 

 glass reflector (as representing a " species " of camera 

 lucida) has often been a snare and delusion to many a 

 young draftsman, and should at once be abandoned 

 by those who are ambitious to do prolonged after- 

 work. 



The best drawing appliance in connection with the 

 microscope is the old \Vollaston "lucida" as im- 

 proved by our present opticians — it is the only tool 

 for the purpose intended — and consists of a prism, in 

 a fitting adapted to the eye-piece. The image of the 

 object is totally reflected upon an oblique surface and 

 carried to a plane at a right angle to its first direction ; 

 the eye looking at the edge of this plane discovers 

 the object, and at the same time its phantom on the 

 paper beneath. As everything is twice reflected, it 

 follows that when the microscope is adjusted for 

 direct vision, the drawing and the object are coinci- 

 dent and not reversed. The only difficulty, and I 

 admit it is a difficulty, and a disadvantage as compared 

 with the ease of manipulating a neutral-tint reflector, 

 is the "knack" required to see the image and the 

 tracing-point at the same time, but it is soon mastered, 

 and is after all a mere matter of practice and experi- 

 ence. In using any form of camera lucida, the pencil 

 once placed on the paper should not, if possible, be 

 removed, or lifted, until the work required to fix the 

 positions is finished ; the eye (unsteady at the best) 

 and the pencil point should be always in unison ; 

 keeping the pencil continually on the paper preserves 

 the "place." 



Mr. Holmes's idea of making pictures upon glass 

 for lantern purposes is most excellent and ingenious. 

 I may add that diagrams for lectures may be effec- 

 tively prepared with an ordinary lantern. Having a 

 fitting carrying objectives of low power, an image may 

 be projected on cartoon paper four feet square. The 

 light is not quite first-rate, but it is sufficient to 

 enable any one to paint in the outlines with Indian 

 ink or sepia. 



One word on the Rev. W. Hey's paper on " Pond 

 Collecting in Winter." It may be news to pond 

 explorers, but now is the time to inoculate an old, or 

 to start a new tank. The sediment, or mud, from a 

 good undisturbed pond, on a heath or common, at 

 the present season, is crowded with resting spores, 

 statoblasts of polyzoa larvse, desmids, and a multitude 

 of dormant animal and vegetable life. A suitable 

 receptacle sufficiently large to contain an inch or two 

 of such sediment, and two or three gallons of water 

 from the same pond, will be as clear as crystal in a 

 fortnight, and reveal a world of life, no collector, 

 skimming with a bottle, could ever hope to obtain. 



E. T. D. 

 Croiuh End. 



