774 INDEX. 



PAGE 



Sewage Fertilization 507 



Sewage, Utilization of 767 



Sex, is it determined by Nutrition 761 



Sexes, Psychology of the 30 



Shadows, Images and. (Illustrated). .• 665 



Shark, The Shovel-nosed. (Illustrated) « 65 



Signaling, Electric 581 



Silk- worm's Thread, its Length 508 



Solar Prominences, The Chromosphere and. (Illustrated) ; 385 



Sounding Apparatus, Improved 255 



Spang Collection of Minerals 433 



Speech, Localization of the Faculty of 125 



Spencer and the Women 746 



u Spencer-Crusher," Another 621 



Street- Sprinkling, Improvements in 124 



Study of Sociology 129, 242, 295, 402, 492, 541 



Substitute for Parchment 123 



Subterranean Fish 639 



Sun's Envelope 127 



Sun-driven Engine 765 



Survival of Instincts 88 



Tarantism 766 



Tennyson and Botany 193 



Tests for Glycerine 510 



Theory of Molecules 276 



Toad, Intelligence of 126 



Transit of Venus, Preparations for the Coming 212 



Trout from an Artesian Well 759 



Typhoid Fever, Etiology of 764 



Unequal Power of the Eyes 379 



United States Naval Observatory 704 



Varieties, Natural 382 



Vegetable Growth, Eapidity of 510 



Vivisection 672 



Walking, Swimming, and Flying. (Illustrated). . .' 528 



Wasps' Nests of Clay 637 



Water-Filters 759 



" Water turned to Blood." (Illustrated) 202 



Weeping-Willow, The 252 



Well, An Ancient, in Illinois 252 



What the Chemistry of the Rocks teaches ... 694 



Work and Influence of The Monthly 747 



Winslow, Forbes 760 



World, The, before the Introduction of Life. (Illustrated) 513 



Year, A, of Geographical Work 735 



Yosemite Valley of Glacial Origin 122 



END OF VOL. IV. 



