154 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(4) Staining and Injecting. 



Methods for Pathological Investigations.* — Dr. V. Babes uses a 

 strong watery solution of safranin by dissolving the dye in distilled 

 water to which 2 per cent, anilin oil is added. The mixture is then 

 heated to about 60° C. and filtered while warm. The solution stains in 

 about one minute ; the sections are then passed through alcohol and oil 

 of cloves and mounted in balsam. Hardening with Flomming's fluid is 

 suitable for this method. According to the author this stain colours 

 calcareous infiltration a red-violet, and is especially suitable for tissues 

 containing bacteria. 



The use of this safranin is also adapted for demonstrating certain 

 pathological changes. For this purpose the tissues are thoroughly 

 stained with safranin and are then placed for a minute in Gram's iodine 

 solution. After passing through spirit and being mounted in balsam 

 the colour is withdrawn, except from certain elements. For example, 

 parts infiltrated with chalk and such as have undergone a colloid change 

 remained stained. The iodo-safranin treatment is especially valuable 

 for staining the club-shaped elements of the Actinomyces. The pus or 

 the crushed Actinomyces is dried rapidly on a cover-glass and treated 

 with anilin safranin for twenty-four hours, decolorized with the iodine 

 solution, and mounted after dehydration and clearing up in clove oil. 



The author also recommends a neutral anilin stain made up of a mix- 

 ture of basic and acid anilins. This neutral stain consists of equal parts 

 of acid fuchsin, methyl-green and orange, and is made by mixing 125 c.cm. 

 of a saturated watery orange solution with 125 c.cm. of a saturated solu- 

 tion of acid fuchsin dissolved in 20 per cent, alcohol ; to this 75 c.cm. 

 of absolute alcohol and 125 c.cm. of a saturated watery solution of 

 methyl-green are then added gradually. The sections are left in this 

 staining fluid for half an hour, then washed and treated with alcohol 

 and bergamot oil. 



In sections thus treated the blood-corpuscles are orange-yellow, the 

 nuclei of the polynucleated leucocytes green, and their cell-substance 

 deep violet, the cell-substance of the eosinophilous cells blackish-brown. 



Staining of Ossification Preparations.! — Dr. H. Klaatsch remarks 

 that it is advantageous to possess a simple and reliable method for 

 demonstrating the process of ossification to classes, for showing students 

 the remains of cartilage in the newly-formed osseous tissue, and for 

 distinguishing the difference between periosteal and cartilaginous ossi- 

 fication. 



These objects may be attained by staining with logwood and decoloriz- 

 ing with picric acid. Grenacher's or Bohmer's hsematoxylin may be 

 used. Overstaining is of no advantage, but if it occur the section must 

 be left for a longer time than usual in the picric acid. Students leave 

 their sections overnight in a watchglass in a mixture of a little aq. destil. 

 plus 6 drops of Bohmer's hematoxylin and 3 drops of glycerin. After 

 being washed in distilled water the sections are transferred to a saturated 

 solution of picric acid until they assume a yellowish-brown colour. 

 They are next placed in glacial acetic acid for about half a minute, and 

 are then washed in distilled water until the yellow colour is no longer 



* Virchow's Arch. f. Pathol. Anat. u. Hist., cv. (188G) pp. 511-26 (1 pi.), 

 t Zeitschr. f. Wiss. Mikr., iv. (1887) pp. 214-5. 



