162 THE AMERICAN MONTHLY [May 



cover them with water to whicli add a little sal soda 

 (aboat au 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. Tiien wash and treat with the cleaning mixture 

 the same as the new tubes. 



Fonnula for ohromic acid clcavhig mixtvre. I 

 80 grams of potassium dichromate in 300 c. • 

 ■water. When all of it is dissolved and the f^oliriiou cooied 

 add it slowly, with constant stirring, to 160 c.c. concen- 

 trated sulphuric acid with constant stirring, storeing t!ie 

 mixture in a glass stoppered bottle. 



A method for cleaning cover-glasses for flag ella 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 cap 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 the- 

 are needed. 



EDITORIAL. 



We wish to call special attention of friends, physicians, 

 and microscopiststo 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 emploj^ed, 



Color of Primitive Man. A wriUr in Knowledge ^\\. .^ ..t. 

 article on this subject illustrated with Photo-micrographf^ 

 but be 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. Cam pliell -if Li vci'p<)< ' 



