318 GOLGI BODIES ETC. 



be given. The wax should be thoroughly removed from the slides, 

 which are brought down to distilled water. Permanganate of 

 potash (§ 711) is then poured on the sections and they are examined 

 under the i or | objective to make sure that the cells are saturated 

 evenly. The oxalic acid is then added, and the slides again 

 washed in distilled water for a few minutes. They should now 

 stain like ordinary chrome-osmium (Champy) slides, in alum 

 hsematoxylin (all day in alum, overnight in hsematoxylin) or by 

 Altmann's acid fuchsin (§ 694). 



717. Osmic Vapour Method (W. Cramer, Imp. Cancer Research Fund 

 Report, 1919). Choose a small glass-stoppered bottle, and place a 

 piece of wide glass tube open at both ends, in the bottom. Arrange a 

 piece of gauze over the top of the inner tube. Add some 2 per cent. 

 OSO4 to the outer vessel. Objects to be fixed by the osmic vapour are 

 placed on the gauze. All the surrounding (fatty) tissue should be 

 removed from the organ or material to be treated ; if too dry the out- 

 side of the material should be slightly wetted. 



The bottle, with object suspended in the OSO4 vapour, is kept at a 

 temperature of 40° C. for one and a half hours. Removed from bottle, 

 the tissue is placed in 50 per cent, alcohol and upgraded and imbedded 

 in paraffin. Cut sections, mount in Ijalsam without staining. Such 

 wax sections may be treated in 10 per cent, hydrogen peroxide in 80 per 

 cent, alcohol for two hours, after which they may be stained in ordinary 

 methods (e.g. iron haematoxylin). 



This method is employed by Cramer for the demonstration of 

 adrenalin in cells of the adrenal glands. 



Gatenby (Quart. Journ. Micr. Sci., 1920) suggests two modifications. 



(a) Fix as above for one and a half hours, and then transfer to 2 per 

 cent. OSO4 in water at 37° C. for several days as for Kopsch. Then wash 

 in water for several hours, dehydrate, imbed and section. Mount 

 unstained, or cautiously treat in permanganate of potash or hydrogen 

 peroxide and then stain in acid fuchsin (Altmann) or iron haematoxylin. 



(6) Tissues may also be fixed as above, and then transferred to 

 Altmann's or Champy's fluid, and subsequently stained in Altmann's 

 fuchsin and picric acid. 



Cramer fixes wet films for about three minutes. We think that a 

 subsequent treatment of films as in above two paragraphs should be 

 useful. The main point to note is that substances in a tissue which 

 might be dissolved out or altered by the water added to the OSO4 

 crystals are fixed in situ, and without the danger of alteration. This 

 method should be of value to histologists and cytologists. 



718. Sjovall's Formol Osmic Acid Method* (Anat. Hefte, Bd. xxx, 

 1906). Superseded by Weigl's method, op. cit. 



Material fixed in formalin, but without chrome salts or platinum 

 chloride, may be used for Sjovairs technique {Anat. Hefte, Bd. xxx). 

 Fix pieces of tissue or small embryos in neutral formalin (5 to 20 per 

 cent, neutralised with magnesium carbonate) for two days. Cut into 

 smaller pieces and wash in several changes of aq. dest. 



Transfer to 2 per cent. OSO4 solution for from two to fourteen days at 

 room temperature, as for Kopsch. Wash well in water, dehydrate clear 

 and imbed. Cut sections 3 [x, if necessary decolourise in peroxide 

 (Solger, § 613) and moimt unstained in balsam. 



719. General Remarks on the Silver Nitrate Golgi Apparatus 

 Methods. These methods all suffer from the disadvantages of 

 * Still the only osmic m ethod possible for formalin fixed human material. 



