THE CHEMISTRY OF LIGHT PRODUCTION 107 



le luminous organs with 90° alcohol in a closed vessel for 

 srelve hours and filtering (1896). (3) By heating the 

 scid luminous fluid to 70° C. Apparently Pholas 

 Lciferin is sparingly soluble in alcohol as it can be ob- 

 lined either in an alcoholic extract (method 2) or by 

 recipitation with alcohol (method 1). Proluciferin 

 jailed preluciferine in- a later paper, 1917 a, 1918 a), is 

 repared by methods 1 or 2 except that fatigued siphons, 

 •om which luciferin has been removed by washing, are 

 3ed (1907, 1917 a, 1918 a). Preluciferin can also be 

 Dtained on boiling an extract of the luminous organ of 

 holas because luciferin (at 70°), luciferase (at 60°) 

 ad a co-luciferase are all destroyed below the boil- 

 ig point (1917 o). 



Co-luciferase is prepared (1) by heating a luciferase 

 )lution to 65° (1917 a) or (2) by extracting with water 

 ortions of the siphon of Pholas which have previously 

 sen macerated and well extracted with alcohol (1918 a). 

 ong-continued treatment with alcohol apparently de- 

 iroys the luciferase without affecting the co-luciferase. 

 n mixing a solution of preluciferin with one of co-lucife- 

 ise and allowing them to stand for 8-10 hours, lucifqrase 



formed and can be recognized by the fact that it will 

 Lve light with a crystal of KMnOi. Preluciferine does 

 it do this. 



Recently Dubois (1918 a) states that preluciferine is 

 jthing but taurine and that taurine occurs in large quan- 

 ties in Pholas and is transformed into luciferine by the 

 ;tion of co-luciferase. Not only taurine, but also Byla's 

 sptone, egg lecithin, and esculin can be converted into 

 ciferiue by co-luciferase, and since esculin, a glucoside, 



so transformed, Dubois believes this proves that co- 



