MORSE. — STUDIES ON FLUORITE. 611 



Discussion of Results. 



As will be seen immediately from the analyses and the corresponding 

 temperatures, there can be no question of the formation of the carbon 

 monoxide in the way which has been suggested by Hiittner. These 

 temperatures are all so low that even if equilibrium had been reached at 

 the temperature of the experiment, which is not at all probable, nothing 

 like the required concentrations of carbon monoxide could result. In 

 fact, in some of the analyses the carbon monoxide equals in concentration 

 the hydrogen, and the relations of the gases are such as would correspond 

 to equilibrium at a temperature above 1000°. Nor can any concentration 

 of the water vapor, which is present in concentrations of the same order 

 as those of the other substances, explain any such results. It seems 

 equally improbable that the carbon monoxide should have been formed 

 from carbon dioxide at any time in the history of the mineral, since the 

 presence of these volatile coloring matters proves that the temperature of 

 the mineral has never been higher than 300°, at which point the color is 

 completely discharged. 



There can be no doubt whatever as to the existence of organic sub- 

 stances in these fluorites. The brown substance which comes over with 

 the water in the distillate can be extracted with ether, and is evidently 

 a product of destructive distillation. I see no reason whatever to ques- 

 tion the statement that the color of the fluorites is due to organic 

 coloring substances. It is perfectly true that there is no relation be- 

 tween the intensity of color in a crystal of this mineral and the amount 

 of carbon and hydrogen found in the analyses. I have examined some 

 perfectly clear white samples which gave a great deal of gas per weight 

 of substance. But it seems to be just as reasonable that certain of these 

 organic substances should be colorless as that they should be anything 

 else, and in the light of this idea all of the conflicting conclusions drawn 

 from the analyses of the past forty years can be easily understood and 

 reconciled. 



The Cavities in Fluorite. 



Microscopically examined, all sections of these fluorites, with the 

 exception of some very homogeneous and clear ones, show many small 

 cavities, each containing liquid and gas. In some cases the distribution 

 of these cavities follows the colored stratified structure of the crystal, 

 but in others the distribution appears to be wholly irregular. The 

 number of these cavities appears to bear no relatiou whatever to the 



