712 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Staining with Phenol and Logwood.— Mr. C. II. Hughes writes 

 us as follows : — 



" Phenol has now and then been referred to, but there seems to bo 

 some doubt as to its value. It is said to destroy delicate tissue and 

 bacteria. I cannot speak decisively with regard to the bacteria, but 

 it has no ill effect whatever on the most delicate tissue, and since 

 1 have used it successfully in staining and mounting spermatozoa 

 (human and animal), I am entitled to think it does not destroy bac- 

 teria, which are hardly more delicate, though of course it kills them. 



I put some chips of logwood in phenol, and in about half an hour 

 have a dark-brown fluid, which stains with great rapidity, and no 

 deposit as with the alcohol and aqueous methods. A small quantity 

 of bicarbonate of soda dissolved in water is mixed with phenol, 

 depositing copiously but leaving some still in solution, and kept as 

 developer. The logwood stain is poured off the section and a few 

 drops of the soda solution poured on, when a magnificent purple is 

 developed. Young bone and attachments of muscles are wonderfully 

 set off. Nigrosin, about 5 grains to an ounce of phenol, is unsur- 

 passed for central system, and seems to act more much powerfully than 

 with spirit. I have been trying for some years to effect solution of 

 carmine in phenol. If a good solution like that of hematoxylin and 

 nigrosin could be effected, no other dye would be needed by the 

 histologist — for tissues, at least. 



If films of bacteria, or of spermatozoa, are exposed to Erlicki's 

 fluid or some of the chromic solutions for a primary effectual coagu- 

 lation of the albumen, I am satisfied the two dyes named would be 

 efficient in strongest solution." 



Staining Pneumonia-cocci.* — Dr. Ribbert recommends the follow- 

 ing for cover-glass preparations, viz. : — 100 parts water, 50 absolute 

 alcohol, 12 per cent, glacial acetic acid, dahlia to saturation. 



The covers are only just touched with the above, washed in water, 

 and examined. Mounted in glycerin or balsam, the cocci appear deep 

 blue, while the capsules are a pale blue. The stain does not last 

 more than a few months. This method is unsuitable for sections. 



Staining Recurrens Spirilla in Blood-preparations. f — Dr. K. 

 Gunther " fixes " very thin layers of spirilla- blood either in the flame 

 of a spirit-lamp or in a thermostat (5 minutes), at a temperature of 

 75° C. Only basic solutions of anilin dyes made with anilin water 

 were found to have any staining power. Of these, gentian violet was 

 found to give the most intense stain (100 cc. anilin water, 11 cc. 

 saturated alcoholic solution of gentian violet). Before staining, it is 

 necessary to wash the cover-glass in a solution of 5 parts acetic acid 

 to 100 parts water for 10 seconds, and after blowing off the greater 

 part of the acid fluid, to neutralize the rest by holding the cover- 

 glass over an open bottle of liquor ammoniae fort, for a few seconds. 

 If this be not done, the deep staining of the blood-plasma and cor- 

 puscles will prevent all but a very few spirilla from being seen. 



* Deutsch. Med. Wochensohr., 1885. p. 13P, 

 t Fortschr. d. Medicin, iii. (1S85) p. 379. 



