J. W. Mallet—Barcenite from Huitzuco, Mexico. 807 
rero. This turns out on examination to be an antimonate of 
hitherto undescribed character, mixed with finely divided mer- 
curic sulphide and antimonic aci 
The specimens given me, one or two of which originally 
weighed more than half a kilogram each, while I saw in Sefior 
Barcena’s possession much larger masses, were for the most 
peeiouely boiled with water to remove air, = 5°348 at 20° C.; 
umps gave notably lower results, owing to porosity. Luster 
