100 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Parkes's "Drawing-room" Microscope. — The peculiarity of 

 this Microscope (apart from its title and golden colour) consists in 

 the revival of the " magnetic bar adjustment " to the stage, a device 

 originated by Mr, G. Busk. 



Piffard's Skin Microscope. — Dr. Stowell recalls * the Microscope 

 for the examination of the skin, devised by Dr. H. G. Piflfard,| to 

 obviate the inconveniences attendant upon a simple lens of high 

 power, which " often involves a constrained position of the head and 

 neck, and in some cases an unpleasant proximity to the subject under 

 investigation." 



Dr. Piffard's description is as follows : — " A (Fig, 12) represents 

 the body of a binocular Microscope made by Nachet, from which the 



Fig. 13. 



Fig. 12. 



^D 



reflecting prism situated above the objective was removed, and another 

 of the same focus but double the size substituted. B is a double nose- 

 piece carrying two objectives of different powers. C is the pinion for 

 fine adjustment (raising and lowering the horizontal arm) ; and D the 

 clamping screw for coarse adjustment, the whole apparatus sliding up 

 and do\vn the rod. E is a rod, five feet in length, which supports the 

 other apparatus, and is itself supported by a cast-iron foot not shown in 



* 'The Microscope,'!. (1881) pp. 33-8. (1 fig.). 



t ' An Elementary Treatise on Diseases of the Skin, for the use of Students 

 sad Practitioners.' (8vo, London and New York, 1876.) See pp. 32-41. (1 fig) 



