514 



THE GARDENERS' CHRONICLE OF AMERICA. 



NEW BUTTERFLY BUSH ( 



BUDDLEYA VAR. 

 MAGNIFICA 



) 



This gorgeous plant is a wealth of bloom from early Summer till frost time. Long panicles of 

 lilac-colored flowers ; beautiful and attractive, especially fine for cutting. As an individual speci- 

 men in the lawn or massed among shrubbery, this plant is well adapted. Strong young stock, 

 will bloom this year, 50 cents each, $5.00 per dozen, $35.00 per 100. 



Write for our catalog. 



IMicheirs Seed House, ^ji Market street. Philadelphia 



clean is second to proper feeding, if not as important ; 

 and cleanliness is probably the best safeguard against 

 insect pests, while proper feeding, in my opinion, is the 

 best single safeguard against fungus pests. 



The day will come, I hope — and it can be hastened ma- 

 terially by a free discussion on the methods you have 

 found best — when growers will practice more closely 

 plant hygiene and build up a hardy type of plant, resist- 

 ant to the many ills ready to fall upon it, but it will not 

 be one method, however, that wins, but a combination of 

 the many that will ultimately rout the fungus and insect 

 pest from our midst. Let us all join hands in this great 

 endeavor. 



SOIL EXPERIMENTS BY THE GOVERNMENT. 



Mineralogical soil analysis has for its basis, according 

 to the Bureau of Soils, U. S. Department of Agriculture, 

 the fact that all minerals, with very few unimportant ex- 

 ceptions, have definite and characteristic optical proper- 

 ties. These properties can be easily determined with a 

 microscope and its accessories, which is specially con- 

 structed for the purpose, a so-called petrographic micro- 

 scope. Therefore by determining the optical properties 

 we immediately find out the mineral. 



All minerals have definite chemical compositions whic'n 

 are well known. Hence, when the minerals of a soil are 

 known, the chemical composition of the soil is also 

 known. Since a mineralogical analysis of a soil can be 

 completed in an hour or less, whereas a chemical analysis 

 would often require days, there is thus an immense sav- 

 ing of time. 



A chemical analysis of a soil shows only what chemical 

 elements are present. On the contrary, a mineralogical 

 analysis shows both the elements present and also the 

 form in which they are combined. This is of importance 

 in judging of the material which the plant will be able to 

 extract from the soil. 



By a study of the soil minerals, a very clear idea of 

 the origin of a soil can be obtained. It is also possible 

 that the method will lead to a mineralogical classification 

 of soils. 



Certain soils in Georgia and elsewhere could not be 

 tilled, because in working them the feet of both horses 

 and laborers became too sore for use. Chemical methods 

 failed to reveal the trouble. A mineralogical analysis of 

 the soil showed that the trouble lay in small siliciou'^, 

 glass-like sponge spicules. 



In the present day study of soil minerals it -has been 

 found necessary to modify largely the methods of both 

 Steinriede and of Delage and T.agatau. Their procedure 

 was both tedious and often inaccurate. At present the 

 soil sample is first analyzed mechanically, thus separat- 



ing the soil into portions in which the grains are all ap- 

 proximately of the same dimensions. Then these por- 

 tions are examined separately. 



The material is mounted upon a microscopic slide in 

 oils of definite refractive indices, and by a comparison of 

 the index of the oil and of the grain the index of the 

 grain is determined. This can readily be accomplished 

 since a mineral grain is not visible when immersed in an 

 oil which has the same index as itself. Each mineral has 

 an index characteristic of itself, and consequently this 

 property goes a long way in identifying the mineral. 

 Certain classes of minerals show up as completely dark 

 when rotated between crossed nicols, a kind of lens made 

 for the purpose. 



The minerals usually found in soils comprise a large 

 number of species, the most important being the follow- 

 ing: Quartz, orthoclasse, microcline, plagioclases, horn- 

 blende, augite, apatite, often calcite, garnet, zircon, rutile, 

 kaolinite, magnetite, hematite, limonite, muscovite, 

 biotite, tourmaline, and epidote. This of course is not 

 a complete list, but it represents the major constituents. 

 Quartz is the predominant mineral of practically all soils 

 and constitutes almost the entire mass of many sands. 

 Orthoclase, microline, and muscovite furnish a large 

 amount of the potash of the soil. Calcite furnishes lime, 

 and apatite, phosphoric acid. 



Recent work on the question of ground rocks and min- 

 erals, such as the feldspars and micas, has shown that in 

 nine soils from New York, Pennsylvania, Virginia, 

 North Carolina, South Carolina, and Alabama, on an 

 average of 260 tons of feldspar and 298 tons of mica per 

 acre to a depth of three feet were present. Since these 

 minerals are present in such large amounts it is obvious- 

 ly not a paying proposition to add them to the soil. These 

 two minerals contain almost ten per cent, of potash. 

 This shows the large amount of potash already in 

 the soil. Apatite, the phosphoric acid mineral, while 

 present in considerably lesser amounts, is widely dis- 

 tributed. 



These results show that the plant food element, pot- 

 ash, and very probably others, are already abundantly 

 present in soils. Not one doubts that fertilizers are ben- 

 eficial. Therefore the cause of the beneficial effects must 

 be sought in another direction than in the theory of 

 simply returning material which has been abstracted from 

 the soil by crops. 



Investigations have recently been conducted showing 

 the effect of alunite and kelp on soils. The results show 

 that the soils treated by each of the fertilizers shows in- 

 creased growth over the untreated soil. The raw alunite 

 used in amounts of 25 to 500 pounds per acre incresed 

 growth from 10 to 20 per cent. The best results were 

 secured with 50 to 100 pounds of potash per acre. 



