92 PREPARATION AND MOUNTING 



CHAPTER Y. 



SECTIONS AND HOW TO CUT THEM, WITH SOME REMARKS ON DIS- 

 SECTION. 



MANY objects are almost worthless to the microscopist until tlie 

 extraneous matter is removed from them ; and this is frequently 

 difficult in the extreme to perform satisfactorily. As an instance, 

 certain Foraminifera may be mentioned in which the cells are 

 placed one upon another, consequently the object must be 

 reduced to a certain degree of thinness before a single uniform 

 layer of thes cells can be obtained to show something of the inter- 

 nal arrangements. 



Most animal and vegetable forms require an examination of the 

 separate parts before much can be known about them. The mass 

 must be divided into separate portions, each part intended to be 

 preserved being cleaned from the useless matter with which it is 

 surrounded. It will frequently be found necessary to make thin 

 sections, which from a very tender substance is no easy matter; 

 and much patience will be necessary to attain anything like pro- 

 ficiency. * 



This making of sections was not until very recently entered into 

 by many except those belonging to the medical profession, but I 

 do not see why this should be so, as much may be accomplished 

 by a persevering and interested mind where there is time for enter- 

 ing into the subject. I will therefore make an attempt to give 

 some instructions on this subject also. We will first consider the 

 cutting of sections from hard substances, in which the ordinary 

 knife, chisel, &c., are of no avail. Most of these require no par- 

 ticular care in mounting, but are placed in balsam like the other 

 objects noticed in Chapter III. : where, however, any special treat- 

 ment is necessary it will be commented upon as we proceed. 



SHELLS, &c. It is seldom, if ever, necessary to possess apparatus 



