118 



CHAPTER IX. 



then washed the superfluous syrup from the surface, and 

 put into ordinary gum mucilage for an hour or so, and then 

 imbedded in the freezing microtome with mucilage in the 

 usual way. 



Cole {Methods of Microscopical Research, 1884, p. xxxix) 

 takes gum mucilage (B. P.), 5 parts ; syrup, 3 parts. (For 

 brain and spinal cord, retina, and all tissues liable to come 

 in pieces put 4 parts of syrup to five of gum.) Add 5 grains 

 of pure carbolic acid to each ounce of the medium. 



(Gum mucilage [B. P.] is made by dissolving 4 ounces of 

 picked gum acacia in 6 ounces of water. The syrup is made 

 by dissolving 1 pound of loaf sugar in 1 pint of water and 

 boiling.) 



The freezing is conducted as follows:— The gum and 

 syrup is removed from the outside of the object by means of 

 a cloth ; the spray is set going and a little gum mucilage 

 painted on the freezing plate ; the object is placed on this 

 and surrounded with gum mucilage ; it is thus saturated with 

 gum aaid syrup, but surrounded when being frozen with 

 mucilage only. This combination prevents the sections from 

 curling up on the one hand, or splintering from being too 

 hard frozen on the other. Should freezing have been carried 

 too far, wait for a few seconds. 



Webb (The Microscope, ix, 1890, p. 344; Journ. Roy. Mic. 

 Soc, 1890, p. 113) takes thick solution of dextrin in solution 

 of carbolic acid in water (I in 40). 



184. Gelatin (Sollas, Q/uavt. Journ. Mic. Soc, xxiv, 1884, pp. 163, 

 164). Gum Gelatin (Jacobs, Amer. Natural., 1885, p. 734). "White 

 of Egg (RoiiLBTT, Denslcschr. math. naturuK Kl. Ic. Acad. Wiss. Wien, 

 1885 ; Zeit. wiss. Mile., 1886, p. 1)2). — Small portions of tissue brought in 

 the white of a freshly laid egg on to the freezing stage, frozen and cut. 

 Oil of Aniseed (Ktjhnb, Centralh.f. Balderiol., xii, 18;i2, p. 28; Journ. 

 Boy. Micr. Soc, 18tl2, p. 706 ; V. A. Mookb, Amer. Mon. Mic. Journ., 

 1894, p. 373; Joura. Boy. Mic. Soc, 1895, p. 247). Anethol (anise 

 camphor), Stbpanow, Zcit. wiss. Mile, xvii, 1900, p. 181. 



For details of these see previous editions. 



For Dollken's method of solidifying formol by means of resorcin, 

 see Zdt. Mu^.«. Mile, xiv, 1, 1897, p. 33. 



