CONTENTS. 
INTRODUCTION. . .cccceece Sete ee eT eA wat Palate os Siaie Mere a saieistah eels, ace 17 
DIVISION I. 
THE ATMOSPHERE AS RELATED TO VEGETATION. 
CHAPrTAK FT, 
ATMOSPHERIC AIR AS THE FooD OF PLANTS. 
i, Chemical Composition of the Atmosphere... 2.2 0.62.5. seccecsseeeesns 21 
§ 2. Relation of Oxygen Gas to Vegetable Nutrition......... ... ae ia ncteeee 22 
§ 3. oe ‘** Nitrogen Gas to “f COE cemeihlause shibeacls Slee seer 26 
§ 4. oe ‘** Atmospheric Water to Vegetable Nutrition................. 34 
§°:5. is * Carbonic Acid Gas ‘ ee OU ete We 34; ret ea tah 38 
§ 6. ‘ * Atmospheric Ammonia to “ pr jp ar ren Reddo g wa eeee ae 49 
(SY so) BAO 1 ae eee a as ee Ethene AL. Se Uae 2 ce ae ho te eee 63 
§ 8. Compounds of Nitrogen and Oxygen in the Atmusphere................. 70 
G24., Other Incredients of) the Atmospheres: ..4.. <..2 220 26>. de eltes gaeeeew ce 91 
§ 10. Recapitulation of the Atmospheric Supplies of Food to Crops........... 94 
pen opinion of Atmospherie Foods: 2i(ccts 2055... d600ip edhe ade aeend 97 
§ 12. Tabular View of the Relations of the Atmospheric Ingredients to the 
A Gg: Sea ee eee Oe ere Maisie wreeiawearn ee 98 
CHAP AH Rh Ler: 
THE ATMOSPHERE AS PHYSICALLY RELATED TO VEGETATION. 
§ 1. Manner of Absorption of Gaseous Food by Plants..........2.ceeeceee see eIY 
DIVISION II. 
THE SOIL AS RELATED TO VEGETABLE PRODUCTION. 
CHAP THE: ~i. 
INTRODUCTORY. .2 360 ost bce Se er tee SR Uicetuad bestows eodutlet tests .,.104 
2 
