Apeil 5, 1895. ] 



SCIENCE. 



377 



market gardener. He finds that "the in- 

 candescent electric light has a marked eil'ect 

 upon greenhouse plants,'' it being " benefi- 

 cial to some plants grown for foliage, such as 

 lettuce. Flowering plants blossomed earlier 

 and continued in l)loom longer under the 

 light ■' than elsewhere. Plants like spinach 

 and endive " quickly ran to seed, which is 

 objectionable in forcing these jilants for 

 sale. Most plants tended toward a taller 

 growth under the light." The fact of 

 plants responding promptly to electi'ic light 

 is widely demonstrated, but that it will be 

 an economical method of growing crops is 

 not so clearly shown. 



SOIL TREATMENT OF ORCHARDS FOR DROUC.HT. 



In many parts of our country crop gi'ow - 

 ing is very uncertain, due to a lack of suffi- 

 cient rainfall. This fact has led the Ne- 

 bra.ska Experiment Station to make a study 

 of methods of mitigating the ill efiects of 

 dry weather. Professor Card* reports re- 

 sults upon an old orchard, a third of which 

 was mowed, a third pastured and the re- 

 maining third cultivated every two weeks. 

 The trees in cultivated ground suffered much 

 less from the drought and hot winds than 

 those in sod, the foliage being more vigorous 

 and without the wilting during the hot 

 windy days common to the trees in the sod 

 ground. 



The fruit was larger and better upon the 

 cultivated trees than elsewhere. An ex- 

 amination of the soil showed that for every 

 100 barrels of water in the first twenty 

 inches of sod ground there were 140 barrels 

 in the cultivated ground. The soil in all 

 regions when drought is experienced needs 

 a covering of mulch. It is not practicable 

 to add a mulch of straw or other material, 

 but the upper few inches of the soil when 

 kept light and mellow serves as a mulch for 

 all below. Therefore a kej* to the solution 



*'Some Obstacles to .Successful Fruit Growing,' 

 Bulletin 39 Xcb. Experimentation Station. 



of the problem is to plow deep ; even sub- 

 soiling will pay for some crops, and then 

 mulch by means of a mellow layer upon the 

 top produced by frequent cultivation. 



THE RUSSIAN THISTLE. 



Xo Other species of plant has received so 

 large amount of attention as has been given 

 during the past two years to the Russian 

 Thistle (Sahola Kali Tragus (L) Moq.). 

 Xot only the botanists have been interested, 

 but law makers in legislative halls have 

 paused in their party strife to listen to the 

 demands of their constituents for enact- 

 ments against this newly arrived and 

 miserable plant pest. 



Many of the Experiment Stations have 

 published bulletins of greater or less size 

 Avith full-page engravings of the thistle in 

 its various parts or conditions of growth. 

 Recently a large emergency poster has been 

 issued by a Central-Western Station to be 

 disjilayed in public places as a means of in- 

 formation and warning to all whom it may 

 concern. The National Government has 

 shared in tliis work by issuing a bulletin 

 from the Department of Agriculture, while 

 Congress was asked to appropriate vast sums 

 to put down this rapidly spreading, prickly 

 weed. 



As the name indicates, this enemy to 

 American agriculture came to our country 

 from Russia, where it is called by a name 

 having the meaning of ' Leap-the-field.' 

 In German it is • Wind witch,' and with us 

 the same idea is embodied in the name of 

 ' Tumble weed,' namely its capacity for 

 traveling with the wind. When it matures 

 in autumn the stem decaj's at the surface of 

 the ground, and the large bu.shy, prickly 

 plant is easily blown for long distances by 

 the wind, and when twenty or so of these 

 plants become entangled and formed into a 

 giant ball the structure is quite formidable. 



The new conditions of the far-prairie 

 States, where a rich soil and open country 



