1897.J MICROSCOPICAL JOURNAL. 7 



The Value of Peroxide of Hydroj^eii in the Prepanitioii of 

 Entire Insects. 



HvCHARI.KS K. HANAMAN, 



TKOV, N. V. 



Tlie use of peroxide of liytirogen in microscopical 

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

 bleaching- of sections which have 1)een bla(;kened by osmic 

 acid or stained green by chromic a<'id hardening' agents 

 and for the rapid ri[)ening (by oxidation) of haematoxy- 

 lin staining tlnids. 



The usnal method of preparing entire insects has been 

 to remove by the Tise of caustic soda or i)otasli all of the 

 soft parts, the resulting pi-eparation consistinji; only of 

 the exoskeleton. Such })reparations are useful for the 

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

 sii-able to make preparations which would show the rela- 

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

 all the parts remained in situ. Such specimens would be 

 esi)ecially useful for comparison with sections and dis- 

 sections of other 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 pre])arations of this kind from the 

 majority of insects. 



Searching for some method by which the o}ia([ue chitin 

 might be rendei-ed transparent without injury to the 

 contained soft parts, I happened to think of peroxide of 

 hydi'Ogen and I believe 1 have found in it the reagent 1 

 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- 

 l)aration of a common house-tly; it being the insect upon 

 which the discovery of the usefulness, in this connection, 

 of the [)eroxide was made. 



Permit me to state here, that my microscopial studies 

 are subject to frequent and sometimes to long continued 

 interru[ilions from business causes, and that nearly all of 



