49 



that for many sections a double stain is scarcely required. The process of 

 staining with it is as follows : — 



First, place the sections in distilled water, then add 20 drops of the log- 

 wood stain to 1 fl. oz. of distilled water, filter, and then place the sections 

 in this for about half an hour. 



Some sections, of course, will require a longer time than others. They 

 must be examined from time to time, and when sufficiently stained should 

 be washed thoroughly in distilled water. They are now to be placed in methy- 

 lated spirit for at least half an hour, when they will be ready for mounting. 



If it is not desired to mount them at once, they can be preserved for 

 any length of time in the spirit. 



Let us now consider the method of double staining in carmine and aniline 

 green. You have all probably seen the directions given in various books on 

 this subject, the whole process occupying something over 24 hours. Doubt- 

 less this plan has answered in some hands, but, although I have spoilt some 

 hundreds of sections in endeavouring to stain them according to the direc 

 tions given, I have never succeeded in getting even fairly good results. 

 When I was almost in despair, my friend, Mr. Martin Cole, kindly showed 

 me a very superior method of staining in borax carmine, and this method, 

 somewhat modified, I have adopted ever since, with the most satisfactory 

 results. One difficulty was ta get the aniline green stain to take a firm 

 hold of the wood and bast tissues, so as not to wash out duinng the soaking 

 in alcohol ; and, after various experiments, I found that the only way to 

 ensure this was to stain the sections with an aqueous solution of the colour, 

 and then to wash them in alcohol and so fix the stain, which, however, clung 

 to them so tenaciously that they would bear soaking in water for a con- 

 siderable time without any fear of its being washed out. I found also that 

 it was necessary to stain with the green before staining with the carmine, 

 since the latter was very speedily removed by water, and required washing 

 in alcohol to fix it. Acting on the knowledge thus acquired, I have now 

 entirely discarded the use of alcohol in all the staining fluids I employ, and 

 invariably make use of glycerine as a preservative in its stead. I should 

 also mention that I have given up the use of iodine green, aud always use a 

 solution of an aniline dye known as " acid green," since I find this gives far 

 better and more reliable results. It can be bought at Messrs. Skilbeck 

 Brothers, 205, Upper Thames Street, E.C., ?lb. of the best quality costing 

 3s. 3d. 



The green stain is prepared as follows : — 



Take of acid green, 2 grs. 



Distilled water, 3 fl. oz. 



Glycerine, 1 fl. oz. 



Thoroughly mix the glycerine and water, dissolve the acid green in the 

 mixture, filter, and preserve in a stoppered bottle. 



The borax carmine stain is prepared thus : — 



(a.) Powdered borax, 10 grs. 

 Distilled water 1£ fl. oz. 

 Glycerine, | fl. oz 

 Journ. Q. M. C, Series II., No. 9. e 



