342 MANIPULATION. 



the spines of the hedgehog, those of certain fish, and some of 

 the larger kinds of whiskers and hairs, the author has adopted 

 with success the plan of making holes in a block of soft wood, 

 and of driving short pieces of them into the holes, as if they 

 were so many nails ; the block is then placed in the machine, 

 and sHces cut from it in the usual manner ; the hairs, from 

 being well supported on all sides, will not shrink from the 

 edge of the knife, but wiU be as easily cut as the wood itself. 

 The sections of the hairs may be readily separated from the 

 wood by laying the wood on a piece of glass with water, and 

 pressing them with a blunt pointed instrument, or tearing 

 the section from around them. The substance known as 

 whalebone may also be readily cut in the machine ; in order to 

 exhibit its structure in the best manner, the sections should be 

 transverse like those of hair. The upper and solid parts of 

 the horns of the antelope, ox, and other ruminants may also 

 be cut in a similar way. Human and other hairs that are far 

 too slender to be sliced separately, may be cut in a mass in 

 the following manner : — If the hairs be made into a bundle, 

 and all dipped together into some thick glue and dried, the 

 bundle wiU become as solid as a piece of wood; this may 

 be cut into lengths, wedged firmly in the machine, and trans- 

 verse sections of the same may then be very easily made; 

 these should be removed from the knife and mounted in 

 Canada balsam with as Uttle separation as possible. Tendons, 

 portions of elastic tissue, and other firm animal structures, 

 when dried, may also be cut in the same manner as the 

 specimens of wood and horn, but, unlike them, they will be 

 found to exhibit no important internal arrangement, except 

 when examined by polarized light. 



All sections of horny tissues, if of a dark colour, should be 

 mounted in balsam; they form, with very few exceptions, 

 beautiful subjects for polarized light, besides exhibiting, in 

 some instances, a remarkable disposition of their pigment ; 

 in the case of human hair, transverse sections are valuable, 

 as proving the cellular arrangement of the Interior, which has 

 been a matter of dispute with microscopists from the earhest 

 times. 



