268 CHAPTER XXII. 



to 2 of gum arable. Rub up the transparent, almost insoluble 

 mass with distilled water, added little by little, then force it 

 through a fine-grained cloth. Repeat these operations until 

 there is obtained a mass that is free from clots. It should 

 then coagulate in the presence of alcohol, undergoing at the 

 same time a dilatation to twice its original volume. The 

 vehicle thus prepared may be combined with any colouring 

 mass except cadmium and cobalt. 



After injection the preparation is thrown into alcohol, and 

 the mass sets immediately, swelling up as above described, 

 and consequently showing vessels largely distended. 



Cold-blooded animals may be injected whilst alive with 

 this mass. It does not flow out of cut vessels. Injections 

 keep well in alcohol. If it be desired to remove the mass 

 from any part of a preparation, this is easily done with 

 dilute acetic acid. 



517. Milk has been recently recommended by FISCHER 

 (Centralb. allg. Path., xiii, 1902, p. 277; Zeit. iviss. Mik. 

 xx, 1903, p. 224). It runs well, does not extravasate, and 

 can be used for auto-injection of the living subject. 



After injection it should be coagulated by putting the 

 organs for at least twenty-four hours into a mixture of 75 

 parts of formol, 15 of acetic acid, and 1000 of water (pure 

 formol will not do). They are then sectioned, and the 

 sections stained with Sudan III or Scharlach R, which stain 

 the milk. They cannot be mounted in balsam. 



Celloidin and other Masses. 



518. SCHIEFFERDECKER'S Celloidin Masses (Arch. Anat. PJtys., 

 1882 [Anat. AbtliJ], p. 201). (For Corrosion preparations). See previous 

 editions ; HOCHSTETTER'S Modification of SCHIEFFERDECKER'S Mass 

 (Anat. Anz., 1886, p. 51); BUDGE'S Asphaltum Mass (Arch. Mik. Anat., 

 xiv, 1877, p. 70), or early editions; HOYER'S Shellac Mass (Arch. Mik. 

 Anat., 1876, p. 645). For this and that of BELLARMINOW (Anat. Anz., 

 1888, p. 605), see early editions ; HOYER'S Oil-colour Masses (Internal. 

 Monatsschr. Anat., 1887, p. 341); SEVEREANU'S, Verh. Anat. Ges., 21 vers, 

 1906, p. 275; PANSCH'S Starch Mass (Arch. Anat. Entw., 1877, p. 480; 

 1880, pp. 232, 371 ; 1881, p. 76 ; 1 882, p. 60 ; 1883, p. 265 ; and a modification 

 of the same by GAGE, Amer. Mon. Mic. Journ., 1888, p. 195) ; TEICH- 

 MANN'S Linseed-Oil Masses (8. B. Math. Kl. KraJcau Alcad., vii, pp. 

 108, 158 ; Journ. Roy. Mic. Soc., 1882, pp. 125 and 716, and 1895, p. 704). 



