1897.] MICROSCOPICAL JOURNAL. 7 



The Value of Peroxide of Hydrogen in the Preparation of 

 Entire Insects. 



Bv CHARLES E. HANAMAN, 



TROV, N. Y. 



The use of peroxide of hydrogen in microscopical 

 technic has, in so far as I am aware, been limited to the 

 bleaching' of sections which liave lieen blackened by osmic 

 acid or stained green by chromic acid hardening agents 

 and for the rapid ripening (by oxidation) of haematoxy- 

 lin staining fluids. 



The usual method of preparing entire insects has been 

 to remove by the use of caustic soda or potash all of the 

 soft parts, the resulting preparation consisting only of 

 the exoskeleton. Such preparations are useful for the 

 study of the sclerites, but it has often seemed to me de- 

 sirable to make preparations wliich would show the rela- 

 tion of tlie muscles and the viscera to the sclerites, while 

 all the parts remained in situ. Such specimens would be 

 especially useful for comparison with sections and dis- 

 sections of otlier specimens of the same insect. 



The dark, and often times opaque, color of the chitin 

 composing the exoskeleton has heretofore prevented the 

 successful making of preparations of this kind from the 

 majority of insects. 



Searching for some method by which the opaque chitin 

 might be rendered transparent without injury to the 

 contained soft parts, I happened to think of peroxide of 

 hydrogen and I believe I have found in it the reagent I 

 was seeking for. 



To illustrate its use, and perhaps at the same time to 

 aid some beginner to make preparations suitable for the 

 study of insect anatomy, I have detailed below the pre- 

 paration of a common house-fly; it being the insect upon 

 which the discovery of the usefulness, in tliis connection, 

 of the peroxide was made. 



Permit me to state here, that my microscopial studies 

 are subject to frequent and sometimes to long continued 

 interruptions from business causes, and that nearly all of 



