I. MICROSCOPES. 923 



3632. Quadrant Microtome, for making microscopical sec- 

 tions at any given angle, with an arrangement for measuring the 

 angle, and scale for showing the relative thickness of the section. 



F. Suss, Marburg. 



3633. Large Microtome, for cutting sections of the brain. 



F. Suss, Marburg. 



These microtomes are suited for embedding preparations. Samples of 

 embedding preparations (soap mixtures), with instructions as to the use of the 

 instruments, as well as the composition of the soap mixtures, are placed with 

 the microtomes. 



3634. Large SchiefFerdecker's Microtome, with plate, 

 two knives in case, glass bell jar, and brass mould for fixing pre- 

 parations in an embedding mass. F. Majer, Strassburg. 



3834-a. Microtome. Dr. Gasser, Marburg. 



This adaptation of the large Gudden microtome has been designed for em- 

 bedding. The object and the enclosing mass being held fast by the screw at 

 the top of the piston, and the often-condemned defect of repeatedly melting 

 down in the case of large objects is avoided. The cylinder is slightly narrowed 

 towards the top, in order that the object may more surely resist the knife 

 which is guided by the hand on a polished steel surface. The instrument 

 can be employed with any suitable liquid in the bowl, which can afterwards be 

 drawn off through a gutta-percha tube, and the object being slightly screwed 

 down, may be covered with a glass slide as a protection against drying up. 

 In this way operations on the same object on several successive days may be 

 carried on. The cylinder is of larger size than in the largest Gudden instru- 

 ment, but can be further enlarged, if necessary, so as to enable sections of the 

 entire human brain to be made. 



3634b. Freezing Microtome, for enabling the microscopist 

 to make thin slices of soft tissues. Invented by Professor Ruther- 

 ford ; made by the exhibitor. Gairdner. 



The freezing microtome was devised by Professor Rutherford for the pur- 

 pose of enabling the microscopist to make thin sections of soft tissues and 

 organs. The tissue is placed in the well ; a strong watery solution of gum 

 arable is poured around it, and a freezing mixture of ice or snow and salt is 

 placed in the box. The sections are made with an ordinary razor. A full 

 description is given in Rutherford's " Outlines of Practical Histology." 

 (Churchill, London, 1875.) 



3635. Smith's Microtome, modified by Schiefferdecker. 



f\ Majer, Strassburg. 



3636. Brass Mould, for fixing preparations in an embedding 

 mass. F. Majer, Strassburg. 



3637. Microscopical Cutting Apparatus, for soft objects. 



Prof. Jessen, Eldena, Pomerania. 



3638. Fluid for keeping Parts of Plants, and preserving 

 their colours in glass vessels. 



Prof. Jessen, Eldena, Pomerania. 



