PUBLICATIONS. 593 
furnaces and other appliances, and accompanied by statistics of pro- 
duction. 
The foregoing constitutes Part I. and is preliminary to the special 
discussion of the Missouri ores and the industry built upon them, 
which forms Part II. This embraces the history of mining in Missouri, 
discussions of the physiography of the mining districts and their 
general geology ; a description of the ore deposits, under the heads of 
distribution, forms, composition, gangues, mineral types, structure 
and mode of formation, and further statistics regarding the lead and 
zinc industry. ; 
Part III. is devoted to a detailed description of the mines in which 
the local occurrence of the ores is set forth with much fullness (200 
pages of fine print, admirably illustrated by sections, sketches, maps 
and photographs). 
To the geologist the chief interest of Mr. Winslow’s important 
report doubtless centers in his discussion of the origin of the ores. 
He points out the grave objections to those hypotheses which postulate 
the derivation of the ores from solutions rising from great depths. 
His own opinion coincides in its main features with those of Whitney 
and Chamberlin respecting the analogous deposits of Wisconsin and 
adjacent states. He assigns the remote origin of the metalliferous 
material to the Archean rocks, whence they were derived by surface 
decomposition. This material he believes was redeposited by the 
oceanic waters in the Palaeozoic sediments whence it was rederived by 
surface decomposition and concentrated in the cavities where it is now 
found. He believes the diffusion of the metalliferous compounds in 
the Paleozoic sediments was general and rejects the view of Chamberlin 
that the localization of the deposits was partly due to local enrichment 
of the oceanic waters corresponding to local richness of the Archean 
areas, partly to the courses the oceanic currents followed and partly to 
the topography of the sea bottom on which the metal-bearing sedi- 
ments were laid down, aided by a differential distribution of the sea 
life which gave rise to the agencies of precipitation. He makes the 
concentration of the ores in the crevices purely secondary, the result 
of local conditions favorable to concentration. He appears in some 
slight degree to have misinterpreted Chamberlin’s view in that he 
makes it inapplicable to rocks of different ages. To be sure the dis- 
cussion of the Wisconsin deposits and the map of the currents were 
made specifically applicable to the Silurian deposits under immedi- 
