208 
began and continued about 4,000 years, clos- 
ing with the introduction of bronze about 
4,000 years ago. 
This makes about 28,000 years since man 
first appeared on Swiss soil; but it must be 
borne in mind that he may have flourished 
in milder parts of the continent for indefi- 
nite ages before that. The vast Alpine 
glaciers rendered the climate of Switzerland 
uninviting long after the continental glacial 
period had ceased. 
MOKI CEREMONIALS. 
AN instructive article for the student of 
primitive religions is that by Dr. J. Walter 
Fewkes on ‘The Group of Tusayan Cere- 
monials called Katcinas.’ (15th Rep. Bureau 
of Ethnology.) It is a faithful narration 
of the strange religious performances, amply 
illustrated, and the native terms preserved 
wherever possible. 
The word Katcina is a vague term for 
spiritual beings of an inferior class to the 
highest deities of the tribe, but who are 
credited with much power over. the welfare 
of the community. They may include the 
ancestral souls, but are not exclusively 
these. The ceremonies in their honor are 
frequent, and distributed throughout the 
year in a ritual calendar devised by the 
priestly class. Both men and women par- 
ticipate in them, and they have the charac- 
ter of a sacred drama, as have most primi- 
tive rituals. Masks, costumes and tradi- 
tional songs and chants are prominent 
features. 
Dr. Fewkes finds noticeable resemblances 
between these ceremonials and those of 
other Pueblos, but also marked differences. 
He is impressed with their analogies to 
those of the ancient Aztecs, and it is likely 
that throughout America numerous coun- 
terparts could be discovered. 
D. G. Brinton. 
UNIVERSITY OF PENNSYLVANIA. 
SCIENCE. 
[N. 8. Vou. VI. No. 136. 
NOTES ON INORGANIC CHEMISTRY. 
Leon Francx details in the Bulletin of the 
French Chemical Society some interesting 
experiments on the formation of metallic 
sulfids by mechanical action. When a mix- 
ture of fine aluminum powder and flowers 
of sulfur is rubbed between two sheets of 
paper, hydrogen sulfid is evolved, owing to 
the formation of aluminum sulfid and its 
subsequent decomposition. The same reac- 
tion takes place between magnesium powder 
and flowers of sulfur. If an aluminum plate 
be rubbed with flowers of sulfur, or even 
with vulcanized rubber, the odor of hydro- 
gen sulfid is distinctly perceptible. With 
those metals whose sulfids are not decom- 
posed in the air the reaction is different. 
When a plate of silver is rubbed with flow- 
ers of sulfur it gradually darkens, owing to 
the formation of silver sulfid, and if the ac- 
tion is continued, little prominences of sil- 
ver sulfid are formed, which can be removed 
by a knife. Copper and lead give the same 
reaction as silver. 
This reaction corresponds to the well 
known darkening of silver coins when car- 
ried in the pocket with sulfur matches. In 
the case of blackening of silver spoons by 
eggs the reaction is somewhat different, as 
the sulfur is in combination and in solution. 
The layer of sulfid must in this case be 
exceedingly thin, for silver spoons which 
have been used sometimes for more than a 
generation have been cleaned again and 
again, perhaps weekly, each time the layer 
of sulfid being rubbed off, and yet the 
spoons show apparently little diminution 
of weight. ‘ 
In the Comptes Rendus, Léon Lémal de- 
seribes the coloring of glass by the direct 
penetration of metals or metallic salts, 
analogous to the cementation process of 
steel making. If glass is covered with a 
silver salt, even in small quantity and 
heated to 500°-550°, on cooling it shows a 
