EUGEN HUSSAK Si 
graphy. In S. Paulo there came together, by accident it may be 
said, a geologist, a petrographic mineralogist, and a chemist, each 
of them a leader in his specialty. These men were Derby, Hussak, 
and Florence. They were to work together, and each was to place 
at the disposal of the others the resources of his own science. 
It may be said of Hussak that all his works were contributions 
to science. He described a large number of new minerals, notably, 
brazilite, lewisite, zirkelite, tripuhyte, derbylite, senaite, florencite, 
chalmersite, and gorceixite. He also pointed out various mineral 
substances of economic importance, such as oxide of zirconium at 
Caldas, platinum in Minas, carbonados and diamonds in S. Paulo, 
corundum in Brazil and in Uruguay, and likewise cassiterite, 
monazite, and several others. 
On mineral deposits he left two noteworthy contributions. 
These were his studies of the gold-bearing beds of Passagem, and 
on the occurrence of palladium and platinum in Brazil. When he 
made this last investigation, he wrote to Russian geologists who 
had sent him materials from the Ural region, calling their attention 
to certain facts that had hitherto escaped their notice. He began 
the systematic study of the heavy minerals of the diamond-bearing 
gravels and added much to the work that had been done by Gorceix. 
On this subject he has left much valuable material unpublished. 
Many years ago he began the preparation of a mineralogy of 
Brazil, and from the large amount of original matter published by 
him on this subject, from the many unpublished observations that 
he had put aside for this work, and from the ability he showed in 
the preparation of a book for instruction, it is evident that such a 
volume would have embraced all of his work as a mineralogist. 
Unfortunately this important work is lost with him. 
Wherever he was known he has left sincere friends. In Brazil 
he leaves no successor. 
