PROCEEDINGS OF SOCIETIES. 281 



Mr. dirties : Podura scale illuminated as an opaque object by 

 Wenliam's truncated lens and paraboloid, with a ^ objective of 

 Gundlacb.* 



Dr. Braitbwaite : Marcbantia-like protballium of Sphagnum cym- 

 bifoUum, sbowing bow it difters from tlie true mosses. 



Dr. Gray : Section of borse's boof, sbowing tbe papillae. 



Mr. G. H. Makins : Crystallized gold, silver, &c. 



Mr. E. Kicbards : Apparatus for tbe more scientific working witb 

 Darker's selenites, 



Mr. E. Wbeeler : Aulocodiscus Kittonii, &c, 



Messrs. Powell and Lealand : Amphipleura pelhicida and N. 

 rliomboides, sbown witb new •j-Vt'^ i^^^b objectives ; and Podura scale 

 sbown under a ^tb incb witb a new adjustment for correcting tbe 

 colour witb different tliicknesses of covering glass. 



Mr. Hailes : Some slides of Foraminifera, from tbe ' Noma' 

 expedition. 



Mr. Fielding exbibited for Mr. Marsball Hall a fine specimen of 

 tbe new sponge, Pheronema Grayii, and slides of tbe spicules. 



Messrs. Boss : Some beautiful injected preparations, and tbeir new 

 immersion glasses. 



Mr. Walter W. Eeeves : ' Glocbidium,' tbe embryo state of 

 Anodonta Cygnea, tbe large fresb-water miissel. 



Mr. Blankley : New portable microscope, witb fine adjustment, 

 aud sufficient rack for a 5-incb object-glass. 



Mr. How : A new lamp. 



Mr. Norman : A portable cabinet to bold 141 slides in tbe space 

 of 7 incbes by 5 incbes. 



Mr. Browning exbibited a series of diffraction spectra of magne- 

 sium, aluminium, and otber metals, tbe metals being burnt by a 

 powerful induction coil, witb a new spark condenser, tbe grating being 

 a series of fine lines, 6480 to tbe Englisb incb, exquisitely ruled by 

 Mr. Lewis Eutberford, of New York. 



Mr. Browning also exbibited one of bis improved micro-spectro- 

 scopes, witb brigbt line micrometer, and sbowed in tbis instrument 

 tbe absorption bands in tbe spectra of tbe following substances, — cbal- 

 colite, salt of didymium, uranus oxide, &c., &c. 



Dr. Pigott exbibited tbe false images and distortions of a gas 

 flame produced by wbat bas been considered a fine \th. objective, and 

 at a later period Pleurosigma formosum, seen witb a i incb by Wray 

 brougbt by bis aplanatic searcber to a power of 1200 linear, witb 

 excellent definition. It was found impossible to sbow tbis ju-operly 

 wbile tbe floor was in vibration from persons walking in tbe vicinity. 



Mr. Fitzgerald : Crystals of silver formed by electric decomposi- 

 tion of a silver salt under tbe microscojie. 



Mr. Ladd : His new arrangement, adapted to ordinary microscopes, 

 for displaying tbe polarizing effects of double axial crystals, tbe field 

 wide enougb to take in botb axes of sugar. 



Mr. Slack : A series of crystals, sulpbate of copper, salicine, bip- 

 puric acid, cblorate of potasb, &c., obtained from solutions containing 

 * See ' M. M. J.,' No. VII., p. 25. 



