198 THE AMERICAN MONTHLY [June 



inch, the long-itudinal lines of Surirellagemma, and the secon- 

 dary structure IstJwiia nervosa with the postag"e stamp frac- 

 ture ; for a one-eig-hth inch or for hig-her powers up to the 

 owe-twelfth the dotted secondaries of Craspedodiscus elegans 

 in certain conditions. 



MICROSCOPICAL MANIPULATION. 



To Stain the Ringworm Fungus. — Adamson recom- 

 mends the following- method for permently staining- trich- 

 ophyton : — 1. Soak the hair in a 5 to 10 per cent solution of 

 caustic potash on a slide for ten to thirty minutes. 2 Wash 

 in 15 per cent alcohol in water. 3. Dry on slide, and in 

 the case of scales fix by passing- throug-h the flame. 4. 

 Stain fifteen to sixty minutes in aniline g-entian violet made 

 in the usual way, by adding- a few drops of saturated alco- 

 holic solution of g-entian violet to aniline water. 5. One to 

 five minutes in Gram's iodine solution. 6. Decolorize in 

 aniline oil two to three hours or long-er. 7. Remove super- 

 fluous aniline oil by blotting- paper. Mount in Canada 

 balsam. — Phar. Jour. 



Frozen Sections. — Ethyl chloride mig-ht profitably be 

 employed in preparing- frozen sections for histolog-ical pur- 

 poses. The results thus far obtained have been exceed- 

 ing-ly satisfactory, and, while the method is somewhat 

 expensive, no accessory apparatus is required for the 

 microtome. 



Hamilton's method of preparing^ the tissues for freez- 

 ing- g-ives g-ood results. Another way of getting- the tissue 

 ready is that recently advised by J. Orth. One hundred 

 parts of Muller's fluid are mixed when wanted with ten 

 parts of formol. Small pieces of the tissue under examin- 

 ation are fixed and hardened in this solution in the incuba- 

 tor for three hours. At the end of this time they are 

 removed and thoroug-hly washed, and alcohol is g-radually 

 added until they are placed in 95 per cent alcohol. This 

 latter re-agent must, of course, be removed before the tis- 

 sue is frozen. If desired, after washing-, the specimen 



