210 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Tho dish is then covered, and the apparatus allowed to rest for 24 hours. 

 On the next day the apparatus is placed in another dish, on the bottom 

 of which is a layer h centimetre high of dried copper sulphate. This 

 dish is half filled with 96 p.c. alcohol. The B tube is now filled with 

 75 p.c. alcohol, and the glass dish haviug been again covered up, the 



Fig. 31. 



apparatus is allowed to work for another 24 hours. By this time the 

 preparation is completely dehydrated. 



Synthetic Alcohol as a Fixative.* — T. E. Oertel recommends 

 synthetic alcohol as a fixing agent for tissues. It is cheaper, and fixes 

 quite as well, if not better, than ordinary alcohol made by distillation 

 from grain. 



Fluid for Softening Chitin.j — Dr. C. Hennings uses the following 

 fluid for softening chitin: — Nitric acid 16 parts; chromic acid - 5 p.c. 

 16 parts ; saturated solution of sublimate in 60 p.c. alcohol 24 parts ; 

 saturated aqueous solution of picric acid 12 parts ; absolute alcohol 42 

 parts. The solution is allowed to act for 12 to 24 hours, according to 

 the size of the object. The object is then washed in 60 p.c. iodine- 

 alcohol, and afterwards passed through alcohols of increasing strength ; 

 then to xylol and paraffin. 



Depigmenting the Eyes of Arthropoda.J — For removing the pigment 

 from the eyes of Myriopoda, Dr. C. Hennings uses a mixture composed of 

 2 parts 80 p.c. alcohol, and 1 part of glycerin, to which 2 vols. p.c. of 

 strong sulphuric acid are added. 



* Journ. Applied Microscopy, iii. (1000) p. 1061. 

 t Zeitschr. wiss. Mikr., xvii. (1900) pp. 311-2. 



t Tom. cit.. pp. 326-7. 



