212 Scientific Intelligence. 
Deducing from this the atomic ratio of the metals to the 
oxygen we have as a result R: O:: 1: 1:331 or as 8: 3-994 
= R,0,, and we find the oxygen ratio of the protoxides to the 
sesquioxides to be as 1: ‘981 or nearly 1: 1. 
The amount of iron protoxide shown in these results was 
found directly in the usual way by potassium permanganate, 
As it has been stated that some varieties of franklinite give 
with HCl a solution containing FeCl,, and at the same time 
evolve chlorine, this variety was quantitatively tested b 
Bunsen’s method with a negative result. Careful experiment 
failed also to show any iron protoxide in the variety first 
analyzed. In both cases, therefore, the total amount of oxygen 
may be said to be fairly determined. 
The results of these analyses give in both cases a ratio very 
nearly corresponding to that of spinel, notwithstanding the 
great differences in the relative amounts of the iron, zinc and 
manganese. 
April 6th, 1876, 
SCIENTIFIC INTELLIGENCE. 
I. CHEMISTRY AND Puysics. 
hydrochloric acid, previously titered. -At the end of twenty to 
¢ : : “eg 
was determined. In two experiments, the oxygen absorbed big 
30°3 and 51-9 milligrams, corresponding to 90°9 and 155°7 ml’ e 
grams of ozone; the heat set free being 118°2 and 223°7 calorie 
calories for the heat set free by conversion of one mo 
ozone into oxygen, and of course —29°6 calories in the 
