SUMMARY "I CURREN'J RESEARCHES RELATING \< 



mission bhrougb a bare crystal plate is still plane polarized, but its plane 

 of polarization bas Buffered a Blight rotation depending on the direction 

 of transmission, and if examined under crossed Nicole does not appear 

 perfectly dark in consequence. In general it may be stated that from 

 an incident plane polarized wave two refracted waves are formed which 

 on emergen© from the plate arc each still plane polarized, but their 

 planes of polarization are not preciselj 90 apart. 



Phenomena of Visual Inhibition which may accompany the 

 re-association of the two Retinal Images dissociated by the Prisms 

 of the Stereoscope. Conditions and determination of these Pheno- 

 mena.*- M. A. Chauveau describes and discusses a series of experiments 

 which tend to evaluate the function of each eye in stereoscopic vision, 

 lb- arranges bo that the two objects viewed differ in detail so as to pro- 

 duce a condition of asymmetry. When a person whose eyes are of 

 unequal visual acuity views such objects through any ordinary stereo- 

 scopic apparatus, the effect seen is dependent on the object presented 

 to the stronger, or dominating, eve. The phenomenon may be very 

 strikingly illustrated by a, suitable choice of asymmetrical objects. The 

 neccssarv condition of asymmetry may also be produced by such means 

 as breathing on one of the prisms. 



11 Avi lock, T. H. — Optical Dispersion: an Analysis of its Actual Dependence 

 upon Physical Conditions. Proc, Roij. Soc, Series A, lxxxiv. p. 492-523. 



(6) Miscellaneous. 



Infinitely Small Chemical Magnitudes.f— P. A. Guye gives an 

 excellent resume of the modern views of molecular constitution. He 

 discusses granules, molecules, atoms and electrons. He pays justice to 

 the useful part played by the Microscope in this important field of 

 research. With the ultramicroscope and arc-lamp illumination Sieden- 

 topf has easily distinguished objects of diameter o*01 /* and, with summer 

 solar light, objects as small as 0-003/*. As the molecules of certain 

 albuminoids are ascertained by calculation to have a diameter of 6 /* ft, 

 it follows that, under certain conditions, molecules can not only be seen, 

 but their calculated magnitude be verified by experiment. While the 

 molecules of gases si em at pit sent to be beyond the reach of vision, yet 

 rerrin by means of an enormous number of microscopic observations on 

 emulsions has established that in an emulsion of uniform granules the 

 distribution of such granuks at various depths is subject tothesame 

 ;iu a8 c ^nect8 the density of the air with its pressure. In other words, 

 Laplace e atmospheric equation 



2 , n 



- "log- = <£(A- 8)g 



8 made a PPlicable to certain solids, [w = mean granular energy • wand 



h " numb rs « I granules at depths h and h„- <f>, the volume of one 



its density; A. the density of the medium; and q the 



due to giavity.] One of the results of the observations 



* g c,,, P ! lii. (1911) pp. 481-7 (3 figs.) 



f ' Schweiz. Natur. Gesell., i. (1910) pp. 168-2CO (6 figs.). 



