As time permitted, tests were run on a variety of 

 organic chemicals purchased from Nutritional Biochemicals 

 Corporation and Eastman Kodak Company„ A variety of aromatics 

 used in perfume manufacture and food flavoring were supplied by 

 courtesy of E„ !„ DuPont de Nenaours and Company, Van Ameringen- 

 Haeblerj Inc„g P, Ro Dreyer, Inc., and Sindar Corporation. Mis- 

 cellaneous substances which were tested included alleged commercial 

 fish attractants and pineapple juice „ 



Preparation 



It is not feasible to describe in detail the method of 

 preparation of each substance which was tested. This has been sum- 

 marized for each experiment and has been included in the appendix. 

 General techniques and procedures, only, will be discussed here. 

 Where necessaryj, details of special preparations will be included in 

 later sections,, 



Simple extracts of fish flesh, skin, gonads, liver, etc. 

 were prepared as follows; a quantity of material (usually about 100 g, ) 

 was weighed, cut into small pieces, placed in a Waring blendor with 

 about 200 ml, of sea or tap water per 100 g. of material, and reduced 

 to a homogeneous suspension of finely-divided particles over a 



5-minute period. The material was then diluted to about 1 liter with 



o o 



water and was placed in a refrigerator (at about 1 or 2 C„ ) for sev- 

 eral hour So The mixture would be used as such, or it would be sepa- 

 rated into liquid and solid components by either filtering or centrifu- 

 ging before testing „ 



A "stock extract" of skipjack flesh was prepared in bulk 

 by grinding 9 pounds of flesh in a nneat grinder, placing this in a 

 nnilk can of 10 gallons capacity, adding tap or sea water to nearly 

 fill the can, and placingthe can and contents in the refrigerator. 

 The solid anaterial would settle from the liquid in a few hours. The 

 clear, amber to cherry-red liquid (the exact color depending on the 

 proportion of light to dark red meat in the sample) could be decanted 

 from the surface,, It was calculated that 1 liter of liquid contained 

 the extract from about 100 g^ of flesh. The stock extract could be 

 maintained without putrefaction for 2 or 3 -/eeks in the refrigerator 

 if the temperature was held just at or above the freezing point. The 

 stock extract was used frequently as a standard in testing other sub- 

 stances. 



In most of the experinnents conducted during the winter 

 and springs 95-percent ethyl alcohol was used in the preliminary ex- 

 traction of ground tuna flesh. The alcohol extract was annber to 



28 



