ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1067 



H.— The Benefits of Improvements in Objectives. 



[Review of the President's Address (R.M .S.) 1886. " No one can read 

 Dr. Dallinger's contributions without a feeling of respect and admiration 

 for those qualities of mind and industry that have enabled him to carry 

 on such difficult observations so long and successfully."] 



Amer. Mon. Micr. Joum., VII. (188G) pp. 172-3. 

 Haechel, E. — [Use of both Eyes with the Microscope.] 



['* According to the same law of divergent adaptation, both eyes also fre- 

 quently develop differently. If, for example, a naturalist accustoms 

 himself always to use one eye for the Microscope (it is belter to use the 

 left), then that eye will acquire a power different from that of the other, 

 and this division of labour is of great advantage. The one eye will 

 become more short-sighted, and better suited for seeing things near at 

 hand ; the other eye becomes, on the contrary, more long-sighted, more 

 acute for looking at an object in the distance. If, on the other hand, the 

 naturalist alternately uses both eyes for the Microscope, he will not 

 acquire the short-sightedness of the one eye and the compensatory 

 degree of long-sight in the other, which is attained by a wide distribu- 

 tion of these different functions of sight between the two eyes. Here, 

 then, again the function, that is the activity, of originally equally- 

 formed organs can become divergent by habit ; the function reacts again 

 upon the form of the organ, and thus we find, after a long duration of 

 such an influence, a change in the more delicate parts and the relative 

 growth of the different organs, which in the end becomes i apparent even 

 in the coarser outlines."] 



Amer. Mon. Micr. Joum., VII. (1886) p. 176. 

 Henocque. — L'Eematoscopie, methode nouvelle d' analyse du sang, basee sur 

 l'emploi dn Spectroscope. (Hrematoscopy ; a new method of blood analysis 

 based on the employment of the Spectroscope.) [Post.] 



Comptes BenJtcs, CHI. (1886) pp. 817-20 (3 figs.). 



Hitchcock, R. — Recent Improvements in Microscope Objectives. 

 [Summarized statement of the modern theory of aperture.] 



Amer. Mon. Micr. Joum., VII. (1886) pp. 190-3. 

 Jorge n sen, A. — Die Mikroorganismen der Garungsindustrie. (The micro- 

 organisms of the fermentation-trades [brewers, distillers, &c.].) 



[Chap, i., pp. 1-24 (6 figs.) Microscopical and Physiological Investigation.] 



viii. and 138 pp., 36 figs., 8vo, Berlin, 1886. 

 Lehmann, O. — TJeber Mikroskope fur physikalische nnd chemische TTnter- 

 suchungen. (On Microscopes for physical and chemical investigations.) 

 [Post.'} Zeitsuhr. f. Instrumentenk., VI. (1886) pp. 325-34 (4 figs.). 



N., W. J.— The Two Mirrors. (In part.) 



[On Illumination by Plane and Concave Mirrors.] 



Sci.-Gossip, 18S6, pp. 217-8, 248-51 (7 figs.). 

 ObiGctivss tli© Nbw. 



[Cf. ante, pp. 316 and 849.] Science, VIII. (1886) pp. 335-6. 



Pelletan, J. — Microscope special de MM. Bezu, Hausser et Cie. pour l'etude 

 des Bacteries. (Bezu, Hausser and Co.'s special Microscope for the study of 

 bacteria.) 



[Hartnack stand with circular rotating stage and glass plate. Abbe con- 

 denser. The objectives are the subject of the following Pelletanian puff. 

 " Every one knows the reputation of the objectives of this house (!). We 

 need not therefore eulogise them here, but we may add that the 1/12 

 homogeneous immersion of MM. Be'zu and Hausser is absolutely of a 

 superior quality. We have several times had occasion to compare it 

 with similar objectives, German, English, or even American, and under 

 all circumstances it showed itself superior by the delicacy and purity of 

 the image, as well as by the absence of colour and distortion of the field. 

 We do not hesitate, therefore, to recommend it in preference to all 

 others."] 



Joum. de Microgr., X. (1886) pp. 412-5 (1 fig.). 



