654 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Preparations which show only the muscular fibre and the elastic 

 tissue may be made by staining small fragments with a mixture, half 

 and half each, of oil of cloves or origanum and concentrated alco- 

 holic solution of safranin and placing for an hour under the air- 

 pump: sections may then be made at once, or, better, uncoloured 

 sections may be transferred from alcohol to the oily solution ; the 

 sections are washed with solutions of caustic potash in alcohol, and 

 mounted in acetate of potash. By putting sections stained with 

 safranin into 30 to 40 per cent, solution of caustic potash the colour 

 is fixed, and the elements come out very distinctly ; they should be 

 mounted in acetate of potash. 



Collodion as a Fixative for Sections.* — Sections fixed by means of 

 a solution of collodion in clove oil, as suggested by Schallibaum,! 

 may be coloured on the slide. S. H. Gage, who had begun to experi- 

 ment with collodion before Schallibaum's method was published, 

 recommends that the collodion and clove oil be applied separately. 



" A solution of collodion is prepared by adding to 2 gr. of gun- 

 cotton (that used by photographers is good) 54 cc. of sulphuric ether 

 and 18 cc. of 95 per cent, alcohol. After the gun-cotton is entirely 

 dissolved the solution should be filtered through filter-paper or 

 absorbent cotton. The slides are coated by pouring the collodion on 

 one end, allowing it to flow quickly over the slide, and off the other 

 end into the bottle. The prepared slides should be kept free from 

 dust. As the collodion will not deteriorate after drying on the slide, 

 any number of slides may be prepared at the same time. Before 

 using a slide it should be dusted with a camel' s-hair brush, and with 

 another brush the collodionized surface of the slide should be thinly 



painted with clove oil The sections are arranged as in 



the shellac method. The slide is warmed over an alcohol lamp, and 

 then heated in a warm chamber, so as to drive off the clove oil. After 

 cooling, it may be placed in a wide-mouthed vial of turpelitine, 

 chloroform, xylol, or refined naphtha, to remove the paraf&n. 

 Naphtha is very cheap, and is the best agent we have yet tried for 

 dissolving the imbedding mass. The sections are usually freed from 

 imbedding mass within half an hour, though the slide may remain in 

 any of the solvents mentioned for two or three days, or perhaps 

 indefinitely, without loosening the sections. When the slide is 

 removed from the naphtha, the sections are washed with 95 per cent, 

 alcohol by means of a medicine dropper, or by immersing the slide 

 in alcohol. If the sections are to be stained in Kleinenberg's hsema- 

 toxylin, or in any other stain containing 50 per cent, or more alcohol, 

 the slide is transferred directly from the alcohol used for rinsing to 

 the staining agent, otherwise it should be first transferred to 50 per 

 cent, alcohol, and from that to the staining agent. Whenever the 

 sections are sufficiently stained, they may be mounted in any desired 

 mounting medium. In case Canada balsam is to be used, the slide 

 must be immersed in alcohol to wash away the stain, and finally in 



* Medical Student (N. Y.), i. (1883) pp. 14-6. 

 t See this Journal, iii. (1883) p. 736. 



