NOTES AND MEMORANDA. 329 



various workers, but to his knowledge they are all deficient in one 

 l^oint, viz. the knife or cutting instrument in them is carried through 

 the tissue like a chisel ; or, in other words, the cutting edge is pressed 

 through the tissue. But a knife, in order to cut well and evenly, 



must be carried through the substance to be cut, especially if it is 

 soft, in a slanting direction, so that each point of the edge describes a 

 curve which is equal to a part of a circle. By referring to the figure 

 it will be seen that in Dr. Seiler's apparatus this is exactly what 

 takes place when the knife is moved, the radius of the curve being tlic 

 length of the arms from the centre of the clamps to the centre of the 

 pivots.* 



Size of Histological Preparations. — Dr. Seiler, in the same article 

 (" Practical Hints on Preparing and Mounting Animal Tissues "), 

 considers that the advantage of having the sections of sufficient size to 

 bring into view the different parts of which it is composed has not as 

 yet received sufficient attention from microscopists, especially from 

 those engaged in the study of pathological histology, and yet it is of 

 the greatest importance, for very frequently a pathological new growth 

 will present different appearances in different parts, and often an 

 erroneous conclusion is arrived at in regard to the nature of the tissue 

 from the fact that but a small section has been examined. 



"Microscopy" and "Microscopical" Societies. — Under the 

 title of " Is there a Science of Microscopy ? " we gave at jjage 3G5 

 of vol. i. an extract from an article by the Editor of the ' American 

 Quarterly Microscopical Journal,' and stated our intention of adding 

 in a later number a translation of an article by Dr. Kaiser, the 

 Editor of the Berlin ' Zeitschrift fiir Mikroskopic.' This intention 

 we are obliged to abandon, as we find it impossible to do justice to 

 the author's views within reasonable limits of space, the article 

 occupying twenty-five pages of the German Journal. It must snfiice 

 here to say that Dr. Kaiser, after referring to Professor Harting's 

 protest against the use of the word Microscopy, and his attempt to 

 contrast it with Ophthalmoscopy (" the science of observation with 

 * 'Amur. Quart. Micr. Journ.,' i. (1879) 134. 



