162 THE AMERICAN MONTHLY [May 



cover them with water to which add a little sal soda 

 (about an ounce to the gallon of water) and boil for 20 

 minutes. Pour off the water and empty the tubes after 

 which again boil them for 5 minutes in clean soap and 

 water. Then wash and treat with the cleaning mixture 

 the same as the new tubes. 



Formula for chromic acid cleaning mixture. Dissolve 

 80 grams of potassium dichromate in 300 c. c. of warm 

 water. When all of it is dissolved and the solution cooled 

 add it slowly, with constant stirring, to 460 c.c. concen- 

 trated sulphuric acid with constant stirring, storeing the 

 mixture iu a glass stoppered bottle. 



A method for cleaning cover-glasses for flagella stain. 

 For this work the ordinary method of cleaning cover- 

 glasses is not sufficient. After being cleaned by the or- 

 dinary method, boil the cover-glasses in an agate cup or 

 glass beaker in a 10 per cent solution of caustic soda for 

 five minutes. After cooling rinse the cover-glasses 

 thoroughly in distilled water after which place them in a 

 beaker and cover with a 1 per cent solution of hydrochloric 

 acid, heat to the boiling point, and allow to stand forsev- 

 eral hours (over night or longer). Then pour the acid off 

 and rinse the cover-glasses several times in distilled water 

 and finally in alcohol. Wipe them out of alcohol as they 

 are needed. 



EDITORIAL. 



We wish to call special attention of friends, physicians, 

 and microscopists to a new and easy method of blood stain- 

 ing - , p. 163, which will prove of great importance in diagnos- 

 ing" disease and especially request that those to whom we 

 take the pains to mail copies will report upon its use as 

 compared with the old methods formerly employed. 



Color of Primitive Man. — A writer in Knowledge g'w e<$> an 

 article on this subject illustrated with Photo-micrographs 

 but he does not commit himself as believingman was either 

 white, brown or black but gives data from which the reader 

 may form his own conclusions. 



Pineal Gland. — Dr. Campbell of Liverpool has described 



