784 SEC. 18. BIOLOGY. 



3662. Preparations of normal anatomy of the human body, 

 injected and varnished, in 1809, by Prochaska. 



The microscope and preparations were given by the author to 

 the first Baron Larrey, with the description in Latin that is 

 affixed to the instrument. Baron Larrey, Paris. 



3662a. Microscopic Section Cutting Machine, with 

 Freezing Cell. Harvey, Reynolds, and Co. 



3662b. Williams' Freezing Microtome. J. Swift. 



3663. Microscopical Double Knife, constructed by A. 

 Kelzig, surgical instrument maker in Prague. The broad blades 

 are, at their free ends, bent towards each other (curved), and are 

 flexible (elastic). Compared with knives of older shapes, the 

 parallelism of the edges is to a much greater extent preserved 

 thereby. 



3664. Valvulotome. An instrument for making incisions in 

 the valves of the heart, being a straight catheter, at whose front 

 extremity, which is rounded, a small knife is attached, which by 

 means of the screw-like motion of a piece of metal inside the 

 catheter can be screwed round its lower fixed end, so that the free 

 rounded end will be more or less moved forward. The edge of 

 the knife is turned towards the catheter. After the introduction 

 of the instrument into the jugular vein, or the carotid artery, the 

 right or left ventricle of the heart can be easily reached. The 

 knife having been moved forward, the chordae tendineae of the 

 heart are grasped and cut off by pulling the knife backwards into 

 the catheter. Artificial disorders of the heart so produced have 

 been observed for more than a year, and the circulation studied 

 on cymographical curves. 



(Prague. Weekly Journal, 76. No. 2.) 



The Imperial and Royal Pathological and Anatomical 

 Institute of the University of Prague (Director, Pro- 

 fessor Edwin Klebs). 



3665. Microscopical Warm Stage. The constant equality 

 of the temperature is obtained by the increased bulk of the thick 

 copperplate. The object is placed in the recess, and the centre 

 aperture of the latter is closed by a glass disc. A broad, tLick 

 copper ring with central aperture for the object is placed on the 

 upper surface of the disc, thus closing the aperture. The lateral 

 movement of the microscope with the coppering is effected by a 

 plate at the bottom of the apparatus on which the microscope is 

 fixed. The same can be shifted in two directions, at right angles 

 to one another by means of micrometer-screws. Four side-apertures 

 admit the introduction of thermometers or liquids for keeping the 



