ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 495 



general purposes of illumination. A second, in which it is shown as applied 

 for projecting microscopic objects, &c. ; it is claimed that as an illuminator 

 for this purpose it is far superior to petroleum lamps as being free from smell 

 and from excessive heat, and at the same time more brilliant. The third is 

 a special form for photographic illumination.] 



Central-Ztg. f. Optik u, Mech., IX. (1888) p. 82 (3 figs.). 



Pulfrtch, C. — Ein neues Eefractometer, besonders zum Gebrauch fur Chemiker 



eingerichtet. (A new refractometer, specially intended for the use of chemists.) 



Zeitschr.f. Instrumentenk., VIII. (1888) pp. 47-53 (2 figs.). 



Seifert. — Ueber das Auer'sche Gasgluhlicht. (On the Auer incandescent gas 



burner.) 



[Recommendation of the Auer von Welsbach light (known in England as the 



WelsbacK) for microscopical observations, examination of the nose, ear, &c] 



SB. Physik.-Med. Gesell. Wiirzburg, 1887, pp. 11-3. 



(4) Photomicrography. 

 Cross, C. F., E. J. Bevan, C. M. King, E. Joynson, and G. Watt. — Eeport 

 on Indian Fibres and Fibrous Substances exhibited at the Colonial and Indian 

 Exhibition, 1886. 



[Contains a description of the photomicrographic apparatus and the method of 

 working, pp. 13-t>, 1 fig.] 



viii. and 71 pp., 5 pis. of photomicr., Svo, London, 1887. 

 [Man ton, W. P., and others.] — Photomicrography. 



[Urging that the " helpful devices and methods " of workers should be " written 

 up and published for the general good, and not held secret for individual 

 benefit."] 



The Microscope, VIII. (1888) p. 89. 

 Nelson, E. M. — On the Formation of Diatom Structure. 



[In exhibiting some photomicrographic positives of diatoms, Mr. Nelson said, 

 " I believe we are on the verge of a new departure in the field of micro- 

 scopical work, viz. illustration by means of lantern pictures from photo- 

 micrographic positives."] 



Journ. Quek. Micr. Club, III. (1888) pp. 201-2 (1 pi. of photomicr.). 



(5) Microscopical Optics and Manipulation. 



Learning to see with the Microscope.* — Mr. E. B. Poulton, in a 

 review of the new edition of Huxley and Martin's ' Course of Elemen- 

 tary Instruction in Practical Biology,' writes on this subject as 

 follows : — 



" The most striking thing in the revised form of ' Practical Biology ' 

 is the reversal of the old arrangement, so that the student is now led to 

 begin with a vertebrate type, and from this to work his way down to 

 the lowest forms of life, and from these again upwards to a type of the 

 flowering plants. There is little doubt that such a change will be met 

 by conflicting criticisms. I believe, however, that the majority of those 

 who have had the widest experience of biological teaching, and espe- 

 cially those who have instructed students in the first use of the Micro- 

 scope, will heartily agree with Prof. Huxley's defence of the alteration 

 in the preface to the revised edition. 



" The process by which the student first learns to see with the 

 Microscope is almost like the education of a new sense-organ suddenly 

 conferred upon a mature organism. We know that under such circum- 

 stances it would be a very long time before the impressions conveyed 

 by the new organ could be harmonized with the well-known experiences 

 resulting from the stimulation of other organs. Accustomed to judge 

 of the shapes of objects by their appearance in three dimensions, the 

 student is suddenly provided with a field of vision in which shapes have 



* Nature, xxxvii. (1888) pp. 505-G. 



