258 E. T. NEWTON ON THE PREPARATION OF SOFT TISSUES. 



as to illustrate the principle upon wLicli most of tlie section-cutting 

 machines used in this country are constructed. 



In the machine described in '' Science Gossip,"* the plug is raised 

 by means of a graduated wedge which passes beneath it, the whole 

 apparatus being fixed to a wooden stand, so tliat it may rest upon 

 the table. This machine being largely composed of wood, would 

 be liable to get out of order when wet with the isj^irit or water used 

 in cutting sections. 



The machine which is generally known as " Topping's," was next 

 described ; in this the plug is raised by means of a screw with a 

 graduated head, so that the thickness of the object made to project 

 above the plate may be easily regulated. There is another addition 

 which this machine possesses which should be noticed, as it has been 

 neglected in some of the forms which have been more recently in 

 use for histological work, viz., a screw at one side of the tube, by 

 means of which the object to be cut may be firmly held or com- 

 pressed. 



Machines of this construction are sometimes attached to a strong 

 clamp, so that they may be fixed upon the edge of a table, thus 

 leaving both the hands of the operator at liberty for manipulation. 



" Stirling's Section Machine" was noticed as being one made 

 specially for histological work. In this form the aperture for hold- 

 ing the object is larger than in those previously mentioned. The 

 top plate with the tube and clamp are cast in one piece, thus giving 

 considerable firmness to the apparatus. The author remarked, that 

 in the machines of this construction, which he had had an oppor- 

 tunity of seeing, the screw for raising the plug was not sufficiently 

 fine, or adjusted with the requisite care, to make the apparatus 

 satisfactory for fine work. These machines do not possess a side 

 screw for compressing the object. 



Dr. Rutherford's addition to Stirling's machine consists of a 

 trough placed around the tube ; by filling this with pounded ice 

 and salt, the object placed in the tube may be frozen, and in this 

 manner made sufficiently hard for cutting into sections. This 

 process of freezing is described in the " Journal of Anatomy and 

 Physiology," 1871, p. 324. 



Quite recently a form of section machine has been manufactured 

 which is really a combination of Topping's and Stirling's, with 

 certain modifications and improvements. The author described 



* Vide Science Gossip, Aug. 1S72, and June, 1873. 



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