300 DE. VINCENT HARRIS. 



1. The only entirely successful combinations were the 

 following ; 



Rosein and anilin green. 



Fuchsin and methylen blue. 



Fuchsin and Bismarck brown. 



Eosin and vesuvin. 



Iodine green and Bismarck brown. 



Hoffman's violet and Bismarck brown. 



Anilin violet and methylen blue. 



2. The green dyes were not at all permanent. I have proved 

 this with both malachite and iodine greens. 



3. Even with the above successful combinations the results 

 varied in a most extraordinary manner, whilst the circum- 

 stances of the staining operation and the solutions appeared to 

 be unvaried, the very greatest care being required to produce 

 a constant result. One thing necessary for success was cer- 

 tainly that the solutions should be quite fresh. This is likely 

 to prove a great objection to the general introduction of anilin 

 dyes into use. The simple method of dehydration employed, 

 of course, could not be employed in the preparation of tissues, 

 although it does for blood, sputa, &c. 



4. The result was materially affected by the time each dye 

 was allowed to remain in contact with the blood. 



It is worthy of note that according to the evidence of com- 

 petent authorities, various chemically diffused anilin dyes have 

 been sold under the same commercial name ; and so, both in 

 the preceding notes and also in the annexed table, it should 

 be said that the anilin dyes used were obtained from Messrs. 

 Hopkins and Williams, Hatton Garden, W.C. The follow- 

 ing table (drawn up August, 1882) includes the dyes used in 

 above experiments : 



I am much indebted to Mr. Meldola, of Messrs. Brooks, 

 Spiller & Co., for valuable information as to the chemical com- 

 position and relations of many of the above anihnes, and of 

 the commercial names, &c., of others. This information he 

 kindly furnished at the request of Dr. llussell. 



