ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 713 



complementary stain. Otherwise tlie gonococci will appear stained blue 

 on a quite decolorized background. 



Dr. F. L. James says * tLat this process differs in scarcely any degree 

 from that wliich he has used for a long time for staining gonococci, and 

 he has found it quite good. The ordinary alkaline solution of methyl- 

 blue stains the gonococci a deeper blue than the surrounding tissues, 

 and does not readily bleach out from the latter. 



Simple and rapid Method of staining Bacillus tuberculosis in 

 sputum. t — M. E. Dineur gives the following as being a very convenient 

 method for clinical purposes for staining the tubercle bacillus : — 



(1^ Saturated alcoholic solution of fuchsin. 



(2) 25 per cent, solution of carbolic acid in glycerin. 



(3) Pure glycerin (or diluted with an equal quantity of water). 



(4) Sulphuric acid, 1 in 5. 



Several drops of sputum are placed in a watch-glass and then mixed 

 with two or three drops of the fuchsin solution. A drop of the car- 

 bolated glycerin is then mixed up with the stained sputum. The mix- 

 ture is then heated for several minutes to a temperature of 80^-100^. A 

 piece the size of a j)in's head is then removed with a needle to a drop of 

 glycerin, placed on a slide, and the cover-glass imposed. A di-op of the 

 sulphuric acid is then run under the cover-glass. As the acid eats its 

 way in, everything but bacilli are decolorized. These retain the stain 

 sufficiently long to be easily recognized by microscoj)ical examination 

 made in the usual manner. 



New Method for staining- the Tubercle Bacillus.^— Dr. K. A. 

 Norderling has devised the following method, which he states is very 

 safe and easy : — 



The staining is done in the usual way by means of the Ehrlich 

 fuchsin solution. The cover-glass is then washed in distilled water 

 and afterwards immersed in a saturated solution of oxalic acid. It must 

 remain therein until it is completely decolorized, when it is taken out, 

 dried, and immersed in a weak solution of methylen-blue until it has 

 received a light-blue colour (about one-half to two minutes). After this 

 it is dried again and finally mounted in balsam. All is now coloured 

 blue except the bacilli, which have a beautiful red colour. 



Staining and mounting Elements which have been treated with 

 Caustic Potash or Nitric Acid.§ — At the Buffalo meeting of the 

 American Society of Microscopists, a communication was read on this 

 subject from Professor Simon H. Gage and Mrs. S. P. Gage. The main 

 features of the technique of mounting histological elements which have 

 been treated during the process of isolation with either nitric acid or 

 potassium hydrate, is as fuUows : — 



When nitric acid has been the agent in isolating the elements, the 

 first step is to soak the latter in water, to remove all traces of free acid • 

 then transfer to a slip of glass on which has been placed a droj) of 

 picrated glycerin. Separate or arrange the fibres, and remove excess of 

 glycerin with blotting-paper. If desired to stain, place in Koch's red 



* St. Louis Med. and Surg. Journ., Ivii. (1889) p. 44, from ' Muncher Med 

 Wochenschrift,' 1889, No. 14. 



t Bull. Soc. Belg. aiicr., xv. (1889) pp. 59-62. 

 X Queen's Micr. Bulletin, vi. (1889) p. 21, from 'Medical Record.' 

 St. Louis Med. and Surg. Journ., Ivii. (1889) p. 233. 

 1889. 3 D 



