366 CONNECTIVE TISSUES. 



in view of any inter-relationship which may exist between the former 

 and the latter. See also BELL (Journ. Med. Research, xxiv, 

 1911, p. 539 ; Journ. of Pathol. and Bad. xix, 1914, p. 105. 

 CIACCIO (Centralblatt f. ally. Pathol. and Path. Anatomic, xx, 1909, 

 p. 771 ; Arch. f. Zellforschung, v, 1910, p. 235. CRAMER, FEISS 

 and BULLOCK (Proceed. Phys. Soc., 1913 ; Journ. of Physiology, 

 xlvi, p. 51. International Congress of Medicine, London, 1913. 

 Section of Pathology). DIETRICH (Erg. d. Allg. Pathologic und 

 Patholog. Anat., xiii, 1909, pt. 2, p. 283 ; Deutsche Patholog. 

 Gesellsch., xiv, 1910, p. 263). KAWAMURA (Die Cholesterinester 

 verfcttung. Jena. Gustav Fischer. 1911). SMITH and MAIR (Journ. 

 Pathol. and Bact., xiii, 1909, p. 14 ; Skand. Arch. f. Physiol., xxv, 

 1911, p. 247). 



769. Fixing and Staining.- -The choice o' : the fixative depends 

 on the question whether the material is to be examined in frozen 

 sections or in paraffin sections. In any case all fixatives containing 

 acetone, alcohol, chloroform or other fat solvents are excluded. 

 For paraffin sections the material may be fixed in osmic acid alone 

 (1 per cent, in solution, or 2 per cent, if fixed in vapour), or in osmic 

 acid mixed with bichromate solution (see fixatives of Flemming, 

 Altmann, Champy). Or it may be fixed in formol bichromate and 

 treated subsequently with a bichromate-osmic mixture (see methods 

 of Schridde and Marchi). As stated in the general part (see 

 p. 363) the different methods give different results with the various 

 groups of fatty substances. For all these methods very small 

 pieces of tissue must be used. For the effects of alcohol on the 

 blackening of certain fatty substances by osmic acid, see HAND- 

 WERCK, Zeit. iviss. Mik., xv, 1898, p. 177 ; MULON, ibid., xxii, 1905, 

 p .138 ; GOLODETZ, ibid., xxviii, 1911, p. 213 ; and Chem. Rev. Fett 

 u. Harzindustrie, xvii, 1910, p. 70 ; LOISEL, C. R. Soc. Biol., 1903, 

 p. 826. 



Another method consists in fixing and mordanting with strong 

 bichromate solution and subsequent staining with Sudan (see below, 

 Bell's method, also Ciaccio) or with hgematoxylin (methods of 

 Weigert for nervous system ; also Lorrain Smith, Dietrich). 



For examination in frozen section the tissue may be fixed in 

 formol saline or formol-bichromate, or the stain may be applied 

 directly to the fresh tissue after teasing. For fine cytological work, 

 the formol should be neutralised by shaking with solid calcium 

 carbonate. HAYS BULLARD (Amer. Journ. Anat., xix, 1916) recom- 

 mends neutralisation and distillation method of GUSTAV MANN 

 (Physiological Histology, Oxford, 1902) : neutralise commercial 



