LECTURES AND ESSAYS READ AT INSTITUTES. 385 



(212 F.) weighed 6.65 grammes, or 39 times the weight of the original seed. 

 Plant 25 inches high when leaves stretched to full hight. 



Wax Beans. The beans while slow to start, made good growth and full 

 development, i. e., jiroduced flowers and seed. Seven plants made this com- 

 plete growth and produced 35 well-developed beans. Some of the plants made 

 imperfect early growth in consequence of difficulty of freeing the cotyledons 

 from the leathery covering of the wax bean, but all that finally grew made 

 sufficient development to mature seed. A pot with three plants was selected as 

 representative because the other pots had only two plants each. The plants 

 were 15 inches high; had in all six pods and 18 beans, besides four unfruitful 

 pods; 41 leaflets, and together weighed in dry state 16.70 grammes, or more 

 than 22 times the weight of the original seed. 



Bed Clover. Plants made a feeble growth at first, but soon manifested a 

 vigor that astonished all. The growth was so strong and the development so 

 complete in a number of the pots that it was difficult to decide which one to 

 take as the best representative, but No. 17 was finally selected. This had four 

 plants with eight stalks in all, measuring 26 to 30 inches in length, 16 clover 

 blossoms and one bud, and a large quantity of vigorous leaves. On taking up 

 the plants the flower pot was lined with crowded and interlacing roots. The 

 dry weight of the four plants was 22.33 grammes, or 3,176 times the weight of 

 the original seed. The relative appearance of the plants in these three pots is 

 exhibited in the photograph bearing the card, 



.SOURCE OF NITROGEN HUMUS IN THE NATURAL STATE. 



There has not been time since taking up the plants to make analysis to 

 determine the increase of nitrogen in the plant over that contained in the 

 original seed. 



HUMUS DEPRIVED OF AMMONIA. 



In order to distinguish between the ammonia of humus and the inert nitro- 

 gen of humus in plant growth, I deprived a quantity of humus of free 

 ammonia so far as could be done by boiling the humus for three hours with a 

 quantity of caustic lime. This humus was then mixed with a quantity (three 

 parts) sand, wood ashes, and superphoshate added as in the first series, and a 

 set of plants grown under the same condition as the first series. The growth 

 of all the plants was less vigorous than with humus in the natural state. The 

 plants were removed from the soil August 8 and dried in a steam bath at 212° 

 F. until no further loss of weight. 



WJieat. Three plants in the pot ; radication superficial and defective ; leaves 

 lifted to full height measured thirteen inches from surface of soil ; the older 

 leaves dead and withered, but newer leaves were green but feeble. The total 

 weight of the three plants 1.05 grammes, or eight times the weight of seed. 



Beans. Four plants in the pot ; roots coarser than in pot containing humus 

 in natural state, and not so well distributed in soil ; plants twelve inches high, 

 and there were eleven matured beans on the four plants ; weight of four plants 

 7.6 grammes, or 7.6 times weight of seed. While the relative weight as com- 

 pared with seed was less than in wheat, the growth was perfect, each plant 

 producing seed, and the eleven matured beans were a striking contrast with the 

 wheat, which gave no hint of formation of head. 



Clover. The clover exhibited a fair amount of vigor, producing stalks 21 

 inches high but no blossoms. The roots were fairly developed and somewhat 

 evenly distributed, but lacking in the mass of fine rootlets seen in clover in 

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