INVERTEBRATA, ORYPTOGAMIA, MICROSCOPY, ETC. 700 



as to always liave a fixed position ou the stage. By mcaus of the two 

 transverse divisions of tlie plate carrying tlie optic ajiparatus, any 

 point of the liquid under examination can be immediately refouud. 

 This is very important in researches on the culture of ferments, which 

 are often under observation for several days, and are continually 

 being modified. The form of the cell rcijresented in the figure 

 renders the Microscope inconvenient for many consecutive observa- 

 tions ; the new plan allows the systems of culture to be multiplied in- 

 definitelj', so as to enable the necessary verifications on any desired 

 point to be made daily. It is only necessary to take precautions 

 when the cell is detached from the stage. 



Tiffany's Prepuce Microscope- — Several arrangements have 

 hitherto been devised fur showing the circulation of the blood in the 

 human subject, so as to obtain assistance in the diagnosis of disease, 

 amongst which are the " Fra)num Microscope " of Dr. Urban Prit- 

 cbard,* and the apparatus devised by Dr. C. Hueter for examining 

 the lower lip, which we recently described under the title of 

 " Cheilo-angioscopy." f 



Dr. Tifiany, of Kansas, U.S.A., suggests + the prepuce as the most 

 suitable part for the examination of the circulation. On account of 

 its thinness, high powers with transmitted liglit are available for 

 the examination. To hold the prepuce in such a position as to render 

 the examination very satisfactory, he uses a thin piece of celluloid, 

 wood, or other light substance, with clamps projecting from tlie under 

 side, which fasten on each side of the lower half of the prejnice, and 

 by thumbscrews at the free end of the instrument render it tense 

 both laterally and longitudinally. Near the attached end of the in- 

 strument is a circular opening, ^ inch in diameter, under which is 

 fastened a thin cover-glass, so that the mucoiis membrane of the lower 

 half of the prepuce lies in contact w^ith this cover-glass. In this 

 position, with the prepuce spread out nearly as thin as the web of a 

 frog's foot, it is clamped upon the stage of the Microsc()i)e, and by 

 transmitted light can be examined by tlie highest powers. A vessel 

 should be selected which is immediately beneath the mucous mem- 

 brane, and it should be pressed (^uite firmly against the cover-glass. 

 Two woodcuts are given, showing the proper manner of applying the 

 clamp and conducting the examination. 



Dr. Tiftany has examined several patients, but " having no status 

 as a guide, has scarcely been able to determine whether what was 

 seen was normal or abnormal." He is, however, satisfied that this 

 method will i)rovo a valuable means of making and confirming diag- 

 nosis of constitutional diseases, as well as a means of watching the 

 progress and effects of therapeutical agents. 



Tolles-Blackham Microscope-stand. — Eeferriug to tlie descrip- 

 tion of this stand at p. Ti'JO, Dr. iJlackhum writes that the snbstage arm 

 is not moved circularly by the milled head B ; it slides freely but 



* Sec Dr. Heiilo'a ' The Mi(.Tosco|io in Medicine,' Itli cd. (1S7)>) p. 503. 

 t See tliirf .lunniul, ii. (187;») p. lUO. 



X 'St. lionii IMfil. iin(l Surj;. Joinii.,' xxxviii. (1880) pp. ,^87-'J. Sec olau 

 ' Loiiiavillc Med. Her.,' ii. (18H0) p. :tO. 



