H2 THE AMERICAN MONTHLY [April, 



present an intense blue color, if methyl violet was used. It is almost 

 impossible to determine the position of the bacilli in relation to their 

 surroundings in specimens so prepared. In order to get the strongest 

 possible contrast between the staining of the bacilli and the cell-nuclei, 

 a yellow or light brown stain is chosen when the bacilli are blue, and 

 when they are red, green or blue is preferred for the tissue ; in the first 

 case vesuvin or Bismark brown is best suited, in the second methyl ine 

 blue. Both of these dyes must be used in weak solutions and their time 

 of action limited. The cover-glass preparation stained inmethvl violet 

 and decolorized in nitric acid and alcohol is then placed, film down- 

 w^ards, in a vessel containing the vesuvin solution. 



From the vesuvin solution the cover-glass is rinsed in water and then 

 allowed to dry in the atmosphere of the room. When it is thoroughly 

 dried it is mounted in Canada balsam diluted with oil of turpentine or 

 xylol. Very thick balsam, which has to be used warm, cannot be em- 

 ployed, as the heating would quickly decolorize the tubercle-bacilli. 



Contrast staining, as a rule, is not required in examining sputum for 

 tubercle-bacilli, so that preparations of sputum mav be examined im- 

 mediately after treatment with the nitric acid and alcohol. They can 

 be examined at once in water, or allowed to dry and then mounted in 

 Canada balsam. 



Sections of tissues that have been hardened in alcohol can be stained 

 for tubercle-bacilli in the same manner as cover-glass preparations. Af- 

 ter staining in the contrast stain, they must, how-ever, be passed through 

 first 70%, then 95%, and finally absolute alcohol, and then cleared in 

 oil of tui'pentine or cedar oil before mounting them in the Canada bal- 

 sam. 



The Koch-Ehrlich-Rindfleisch rapid method of staining tubercle-ba- 

 cilli is reported by Dr. E. O. Siiakespeare* as giving constantly satis- 

 factory results, both as to reliability and rapidity. With it the examin- 

 ation of sputum or other fluid or semi-fluid material for the presence 

 of the tubercle-bacilli requires no more time and trouble than the ex- 

 amination of urine for tube casts, and often not so much of either. 



The method is Ehrlich's, modified by heating the staining fluid con- 

 taining the specimen over a spirit or gas flame until bubbles begin to 

 appear. Remove the heat at once and allow the cover-glass to remain 

 in the hot fluid from two to four minutes. Then remove it, immerse it 

 in acid, then alcohol, and so on as described above. 



Philip Henry Gosse was born at Worcester, England, in iSio, 

 and died at Marychurch, April 23, 1S8S. Among his early works 

 w^ere " The Canadian Naturalist" (1840) and '• The Birds of Jamaica " 

 (1851), "A Naturalist's Rambles on the Devonshire Coast" and 

 The Aquarium (i853-'4). Of greater importance was his " Manual 

 of Marine Zoology" (iS55-'6), and " Actinologia Britannica." The 

 latter is still an authority on sea-anemones and corals of the British 

 Isles. To microscopists his work on the Rotifera in connection A\ith 

 Dr. C. T. Hudson is invaluable. All his works were finely illustrated, 

 he being an ingenious artist. 



* Journal of Comparative Medicine and Surgery, 1887, p. 241. 



