110 COLLODION AND OTHER IMBEDDING METHODS. 



hardens for an hour iu vapour of formaldehyde, and soaks for a few 

 minutes in fonnol of 10 per cent. ANITSCHKOW (ibid., xxvii, 1910, 

 p. 73) puts them into alcohol of 50 per cent., gets them on to a slide 

 prepared with Mayer's albumen, presses down with paper, puts into 

 alcohol of 98 per cent., and thence through lower grades into water. 



183. Gum and Syrup Masses. HAMILTON (Journ. of Anat. and 

 Phys., xii, 1878, p. 254) soaked tissues in syrup made with double 

 refined sugar, 2 ounces ; water, 1 fluid ounce ; 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 5 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 muci- 

 lage ; it is thus saturated with gum and 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 (1 in 40). 



184. Gelatin (SOLLAS, Quart. Journ. Mic. Soc., xxiv, 1884, pp. 163, 

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

 of Egg (ROLLETT, Denskschr. math, naturw. Kl. k. Acad. Wiss. Wien, 

 1885 ; Zeit. wiss. Mile., 1886, p. 92). Small portions of tissue brought 

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

 Oil of Aniseed (KUHNE, Centralb. f. Bakteriol., xii, 1892, p. 28 ; Journ. 

 Eoy. Mic. Soc., 1892, p. 706 ; V. A. MOORE, Amer. Mon. Mic. Journ., 

 1894, p. 373 ; Journ. Eoy. Mic. Soc., 1895, p. 247). Anethol (anise 

 camphor) (STEPANOW, Zeit. wiss. Mik., xvii, 1900, p. 181). 



For details of these see previous editions. 



For DOLLKEN'S method of solidifying formol by means of resorcin, 

 see Zeit. wiss. Mik., xiv, 1, 1897, p. 33. 



