294 



of the accuracy of Von Recklinghausen's views on the sub- 

 ject, for which we refer the reader to ' Strieker's Handbuch.' 

 We caution our readers that those who discard the silver- 

 method are those who have not had the skill to obtain the 

 results which it can afford. 



Microtomes. — We have to notice the microtome of His 

 (Schultze's Archiv, 1870, 2nd part) ; of Ranvier, made by 

 Verick, of 2, Rue de la Parcheminnerie, Rue St. Jacques, 

 Paris ; of Stirling, of Edinburgh, described in the last 

 number of the ' Journal of Anatomy and Physiologv ;' and of 

 that of M. G. Rivet, also made by M. Verick. That of Prof. 

 His is by far the most complex and important, and is a 

 modification of one devised by Prof. Hensen. We cannot 

 now describe it in detail, but we do not think any results 

 can be obtained by its use which the educated hand will not 

 give. Ranvier's and Stirling's microtomes are both adajDta- 

 tions of the old section machine described long ago in 

 Carpenter's ' Microscope.' They are very useful, as Dr. 

 Cleland testifies in our April number. The chief point in 

 Dr. Ranvier's little instriiment is the use of elder-pith to sur- 

 round the object to be cut; this is then squeezed into a 

 cylinder with a broad flat top, and is worked up from below 

 by a screw ; the razor is drawn steadily across the flat top, 

 and good sections of such objects as the spinal cord or a 

 Avorm are obtained at once, even by the beginner. M. Verick 

 supplies this instrument for ten francs. Mr. Stirling's differs 

 only in being larger and fixed to the table. The microtome 

 of Rivet is a very pretty thing admirably adapted, we would 

 suggest, for cutting cucumbers, if constructed on a larger scale ; 

 and certainly useful where it is wished to take many micro- 

 scopic sections. Two grooves in a block of wood run 

 parallel to one another, but one forms a slight incline ; along 

 this groove runs a clip holding the object to be cut, along the 

 other groove runs the knife fixed at a suitable angle for 

 cutting. The movement of these two bits is managed by the 

 hand, the grooves being deep and the clip and knife being 

 attached to large bits of wood which run firmly in the 

 grooves. The knife having been made to cut a piece of the 

 object held by the clip, it is clear that a slight movement of 

 the latter up its inclined plane will raise it a very little, and 

 when the knife is again drawn along, a very thin section, 

 depending for thickness on the amount which the clip was 

 pushed along, is obtained. 



