312 DR A. J. WHITING ON THE 



cellular elements. The method of fixing the tissue by a saturated solution of corrosive 

 sublimate proved to be very good for the spleen. The solution was sometimes used 

 warm, and sometimes 075 per cent, sodium chloride was added. Small pieces of tissue 

 were placed in this solution for about half-an-hour, after which they were thoroughly 

 washed in water, normal salt solution, or dilute alcohol, and were then taken through 

 successive alcohols of increasing strength, and left in methylated spirit until sufficiently 

 hardened. 



Sections were made in two ways — after freezing the tissue saturated with gum and 

 after imbedding in paraffin. Each was found to be preferable for different purposes ; in 

 studying the cellular elements of the pulp, the giant cells were best shown by the gum 

 method, and the erythroblasts by the paraffin method. The former was of special service 

 in allowing of the detachment of the cellular elements of the pulp from the reticulum. 

 We found the gum method the more generally preferable. The method of " shaking " 

 the sections was found to be better than that of pencilling them, because it was practi- 

 cally impossible to remove the free cells without removing large portions of the stroma 

 as well. Sections previously stained were placed in a wide test tube with water or 

 normal salt solution, and the tube was gently shaken for about a minute. The sections 

 were always broken up into several pieces of varying size, and this was advantageous, 

 as the reticulum was revealed best near the free edges of such small pieces. 



In staining the sections, no method proved so valuable as that of using hgematoxylin 

 followed by eosine. Sections were placed in a solution of the former, in the strength 

 of one to twenty of distilled water, for about ten minutes ; they were then washed in 

 distilled water and allowed to remain in a 1 in 2000 watery solution of eosine for two 

 or three minutes. The eosine was of special use in acting as an energetic stain for 

 protoplasm containing haemoglobin. Picric acid in saturated alcoholic solution was 

 sometimes used instead of eosine. Ehrlich's acid hsematoxylin gave good results. 

 Ehrlich-Biondi's triple stain, of methyl green, acid fuchsine, and orange, was occa- 

 sionally used, but was of no special advantage. The sections were sometimes mounted 

 in Farrant's solution, but generally in Canada balsam. 



The splenic tissue was often examined in the fresh state, sometimes in the form of 

 a simple scraping, but usually diluted with a normal salt solution tinted by methyl 

 blue. Portions of scrapings diluted with aqueous humour or hydrocele fluid were 

 placed between cover glasses, rung with oil and examined on Schafer's warm stage. 

 Films were made by drawing cover glasses over the cut surface of the spleen, and 

 then either dried in the air and stained with alcoholic solution of methyl blue, or, what 

 we found much better, on Dr Muir's suggestion, fixed by a warm saturated solution of 

 corrosive sublimate for half-an-hour, taken through successive alcohols, stained with 

 Ehrlich's acid hsomatoxylin, and subsequently, in some instances, with alcoholic 

 solution of eosine. The surplus hamiatoxylin was removed by washing in acid alcohol, 

 and the films were cleared with clove oil before they were mounted in balsam. The 

 blood films, after being dried in the air for not less than twenty-four hours, were stained 



