[The Copyright of Articles in this Journal is Reserved.} 
CONTENTS OF No. LXI. 
PAGS 
PArt. 
x. On the Thickness of the Antarctic Ice, and its 
Relations to that of the Glacial Epoch. B} James 
Croll, LL.D., F.R.S., of H.M. Geological Survey . ■ I 
II. Gravitation as a Factor in the Organic World. By 
William Crookes, F.R.S 34 
III Sanitary Science in the United States: its Present 
and its Future. By Albert R. Leeds, Ph.D. • • 49 
IV. The Course of Nature. By Prof. Simon Newcomb . 64 
V PeruvianAntiquit.es. By E. R. Heath, M.D., Wyandotte, 
, . • 09 
notices of scientific works. 
Fowler’s “ Bacon s Novum Organum 
Lord Rayleigh's “ The Theory of Sound ” ... . 
Prodtpr’s “ The Moon, her Motions, Aspeft, Scenery, and Physical 
Condition.” ••••■* 
Gore’s “ The Art of Scientific Discovery ” 
Baynes’s “ Lessons in Thermodynamics ” 
Magnus’s “ Hydrostatics and Pneumatics 
Jenkin’s “ Electricity and Magnetism ” 
Muir’s A Text-Book of Arithmetic for Use in Higher School 
Classes ” 
Tait’s “ A Treatise on the Dynamics of a Particle ”... 
“ Report of the New Jersey State Commission appointed to devise 
a Plan for the Encouragement of Manufacturers of Orna- 
mental and Textile Fabrics ” . . . . 
leg 
no 
in 
112 
112 
m 
114 
114 
114 
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