new thorium and uranium Mineral. 103 



The above ratios are as close as could reasonably be expected. 



It will be interesting to compare the molecular ratios of the 

 theoretical mineral with those found for the analyses of mack- 

 intoshite and thoro-gummite and to notice the sharp relation- 

 ships brought out. 





Mack 



mtoshite. 







Theory. 



Molec. 

 ratio. 



Found. 



Molec. 

 ratio. 



Error. 



3Si0 2 = 13-87$ 

 ICOo 20-95 

 SThOo 61-02 

 3H 2 4-16 



= 2311 



7-70 



23-11 



23-11 



Thoro 



13-90$ 



22-40 



60-35 



4-31 



gummite. 



= 23-16 



8-23 



22-86 



23-94 



= +0-03$ 

 + 1-45 

 -0-67 

 + 15 



Theory. 



Molee. 

 ratio. 



Found. 



Molec. 

 ratio. 



Error. 



3SiOo = 13-16$ 

 IUO3 21-05 

 3ThOo 57-89 

 6H0O 7-90 



- 21-93 



7-31 



21-92 



43-83 



13-08$ 



22-43 



57-60 



7-88 



= 21-81 



7-4 7 

 21-82 

 43-77 



= -0-08$ 

 + 1-38 

 -0-29 

 -0-02 



In conclusion I wish to reiterate the purely conjectural char- 

 acter of the above tabulated results and to repeat the wish of 

 Dr. Hillebrand that more of this new mineral may be found so 

 that its true composition and formula may be known beyond 

 all question or doubt. That the mineral is more basic than 

 either thorite or uranothorite* seems at once obvious. 



I propose the name of mackintoshite for this new species 

 in honor of the able chemist, the late Mr. James Buckton 

 Mackintosh of New York City. The name seems peculiarly 

 appropriate because of the large amount of valuable work 

 which he did in mineralogy and especially since the mineral 

 contained an earth — thoria — to which he had given an especial 

 study. 



*Lindstrom's analysis of uranothorite gives, by calculation, the ratios of 1 : 1:51 

 for silica, bases and water and shows no apparent ratio for the uranium to the 

 other bases. 



