1897] MICROSCOPICAL JOURNAL. 265 



apparently free from stain; this will take from fifteen to 

 thirty minutes. 



(8) Double stain with a solution of orang-e (1 per cent 

 of saturated watery solution of orang-e to 20 to 40 parts of 

 50 per cent alcohol). 



(9) Dehydrate with absolute alcohol. 



(10) Clear very rapidly with xylol. 



(11) Mount in xylol and Canada balsam. 



A New Method of Staining Nervous Tissue. — Vasta- 

 rina-Cersi (Rif. Med., Feb. 14, 1896.) describes a new and 

 effectual method of staining- the spinal cord, etc., for 

 macroscopic purposes. The entire cerebro-spinal axis, 

 with the mening-es, is plung-ed into about 3 litres of an aque- 

 ous solution of formaldehyde (16 per 1000). The tissue is 

 left in the medium for two weeks, the mening-es being- 

 removed on the second or third day. Sections from 3 to 5 

 cm. thick are then cut and kept in distilled water, or, better 

 in alcohol at 40 degrees, for twelve or twenty-four hours; 

 then plung-ed into 75 deg-rees solution of AqN03 in the 

 dark. The white substance soon becomes stained brown. 

 A prolong^ed stay in the AqNOs sol. does no harm. The 

 stain may be fixed for an indefinite time if the preparation 

 s left for two or three days in the dark in distilled water 

 and then in alcohol at 70 deg-rees. Tissue so prepared 

 shows in the clearest manner the relations between the 

 white and the g-rey substance. For example, in the medulla 

 one could distinctly see with the naked eye the respiratory 

 fascicules of Krause. The advantag-es claimed by the 

 author for this method are its simplicity and rapidity of 

 execution, the constancy of the results, and its g-reat 

 teaching- value. — Brit. Med. Journ. 



BACTERIOLOGY. 



Potato Agar.— Dr. H. M. Richards, of Barnard Colleg-e, 

 has proven the potato ag-ar to be of g-reat service. It is 

 prepared as follows : Three or four medium-sized potatoes 

 are washed, pared, cut into pieces and boiled in one liter 



