JIOUNTING OBJECTS IN CANADA BALSAM. 



303 



Messrs. New and Bond, ingenious preparers of microscopic ob- 

 jects, a notice of it in print appears in a small book published 

 by Mr. Pritchard, in 1835, entitled A List of Two Thousand 

 Microscopic Objects. The older anatomists were in the habit 

 of using varnishes of different kinds to cover their injected 

 preparations, which, in course of time, became hard and trans- 

 parent ; the obj ects belonging to the microscopes described in 

 page 16 are thus coated. Mr. Pritchard* gives the first 

 account of mounting objects in a fluid which subsequently 

 became hard and rendered the mounting permanent; this is 

 said to have led to the employment of Canada balsam for the 

 same purpose. It will be found convenient to have two kinds 

 of balsam, one in a very fluid state, the other much older and 

 thicker; these should be kept in wide-mouthed bottles that 

 can be sufficiently closed to prevent all dust from getting in. 

 The best vessels for the purpose are small glass jars with large 

 tops similar to that represented in fig. 209. The balsam is 

 taken out of these by a small glass rod, which should be of 

 a sufficient length to project above the neck of the jar, so as 

 to be covered up with the balsam ; the jar should not be more 

 than half full, the rod will then be sufficiently uncovered to 

 allow of its being handled without soiling the fingers, a point 

 that should be particularly attended to. 



Wooden Forceps. — For this very useful instrument we are 

 indebted to the ingenuity of Mr. Julius Page : in the upper 

 part of fig. 206 is shown its application to the holding of a 

 Microscopic Cabinet, p. 230. 



