79(5 



SOMMARY OF CURRENT RESEARCHES RELATING TO 



Ganz's Pinakoscope with Dreyfus's Reflector. — Herr J. Ganz's 

 instnuneiit, wliicli was cxliibiteil at the Wiusbatleu Exliibition last year, 

 is practically Ji Sciupticoii,* but for microscopic purposes it is fitted with 

 a stage and carrier for objectives. Mr. L. Dreyfus (uow of Wiesbaden), 

 has added a reflector fixed in a short tube which can be pushed over the 

 end of the tube carrying the objective (fig. 127), so that the images in 

 place of being shown on a screen, can be thrown on the table, an arrange- 



FiG. 127. 



ment which is very effective for drawing objects. Mr. Dreyfus writes, 

 " By the aid of this apparatus we make all the drawings used in the 

 lectures here with perfect ease, sitting at the table. The drawing can 

 be left, and finished whenever we have time again." 



The illumination being obtained from a mineral-oil lamp is not 

 strong enough to show objects under powers higher than a 2/3 in. 

 objective. 



Tri-ocular, Q,uadri-ocular, &c., Prisms. — Figs. 128 to 132 show the 

 various prisms belonging to the Microscopes described in this Journal, 

 1887, pp. 796-800. Fig. 128 is the prism over the objective of Nachet's 

 double-bodied Microscope, fig. 129 that of Nachet's triple-bodied, and 

 fig. 130 the small four-sided prism for which M. Nachet (pp. 1067-8) 



* Cf. J. Schcrrer, ' Das Pinakoskop und seine Anwenduiip;,' &c., 01 pp. and 30 figs., 

 8vo, Speicher, 1886. Cf. also Boll. Accad. Med. Roma, 1886, pp. 17S-U2. 



