610 



SCIENCE 



[Vol. LV, No. 1432 



animals are practically identical. Even the tiny 

 muscles moving the wings of insects, such as 

 the fly and the mosquito, resemtole microscop- 

 ically the muscles of man. 



If man was a special creation, the Almighty 

 was not limited to the lowliest form of matter— 

 the "dust of the ground" — as material for the 

 himian body. He could have created a nobler, 

 a more subtle, a more puissant and exalted stuff 

 out of which to fashion man. The plan and 

 structure and function of man's body would 

 then supposedly have differed toto coelo from 

 man's present body. Probably it would have 

 been free from the defects and deformities 

 inherent to the animal body, and free from the 

 diseases which it shares with animals. 



But, no! God deliberately made man out of 

 the same stuff as the animals, and, as I have 

 shown, on the same plan as animals. Body- 

 wise, man is an animal, but, thanks be to God, 

 his destiny is not the same as that of the beasts 

 that perish. To develop great men, such as 

 Shakespeare, Milton, Washington and Lincoln, 

 and then by death to quench them in utter 

 oblivion, would be unworthy of Omnipotence. 

 To my mind, it is simply an impossible con- 

 elusion. Man's soul must be immortal.^ 



* * * * * s- 



W. W. Keen . 



CULTIVATION AND SOIL MOISTURE 



The question of cultivation in relation to soil 

 moisture is one on which there has been differ- 

 ence of opinion among agricultural workers. 

 The work of Professor Call of Kansas has 

 tended to show that (under his conditions) 

 cultivation, as cultivation, does not conserve 

 soil moisture. 



Since 1913 the writer has been engaged in 

 agricultural work where the question of culti- 

 vation in relation to the conservation of soil 

 moisture has been important. In the earlj- 

 years -of this work the surface mulch idea, 

 which is quite generally accepted by agricul- 

 turalists, was believed and used to explain the 

 presence of ample moisture under cultivation 

 when there was a deficiency without cultiva- 



5 The full address will appear in the Philadel- 

 phia Puhlic Ledger for Sunday, June 11. 



tion. When other features of plant growth 

 were investigated some effects of cultivation, 

 other than moisture, were brought out. 



The recent controversy between Dr. Jerome 

 Alexander and Mr. L. S. Prierson in the Sep- 

 tember 2, 1921, the February 10 and March 24, 

 1922, issues of Sciexce has been interesting. 

 One of these writers accepts the general view 

 that cultivation of the surface of the soil con- 

 .serves soil moisture by preventing surface evap- 

 oration, while the other does not believe that 

 this is in accord with engineering experience. 

 If our woi'k had shown that, in cultivation, we 

 were dealing with a moisture factor alone, the 

 writer might agree with one of these two men 

 without going into the specific conditions 

 under which the data were obtained. Our work 

 has shown that cultivation changes the com- 

 position of the soil solution and has an effect 

 on the water requirements of the plants grown. 



The Journal of Industrial and Engineering 

 Chemistry for March, 1922, Vol. 14, No. 3, 

 has the following in an article by the writer in 

 discussing a composition basis for the water 

 requirements of plants: "There is a common 

 saying, cultivate to conserve soil moisture and 

 you will have larger crops. The author be- 

 lieves that cultivation lets air down into the 

 soil, thereby increasing bacterial activities 

 which in turn cause the plants to get more 

 food and grow larger on less moisture, woidd 

 be nearer the truth. Experiments are reported 

 where fertilization has decreased the- water 

 requirements of plants over one half, when 

 expressed as the amount of water necessary 

 to produce one unit weight of plant. 



In the field experiments we had plants grow- 

 ing well, with cultivation, when on the same 

 soil without cultivation^ lack of water in the 

 soil was hindering plant growth. It was easy 

 to say that these were the results of cultivation 

 in conserving soil moisture but to find out how 

 the mulch conserved the soil moisture was a 

 problem for intensive study. The evident facts 

 were that the well cultivated crops were not 

 suffering from lack of water in the jDeriod of 

 dry weather. 



It was found that the soil having the water 

 reserve had a higher concentration of plant 

 food and the plants growing in this soil con- 



