mvisiox OF SOILS. 77 



CHEMICAL SOIL INVESTIGATIONS. 



The chemical work of the Division has Ijeen done, so far as practi- 

 cable, with the cooperation and support of the Division of Chemistry. 

 Papers relating solety to chemical subjects and having no particular 

 bearing on soils, which have been prepared in this Division, have been 

 published through the Division of Chemistry. The results of chemi- 

 cal soil investigations have been submitted to Dr. Wiley for his 

 approval, in accordance Avith the present policy of the Department. 



The chemical methods emijloyed by the held parties have been 

 closely scrutinized and improved in some details. The field parties in 

 the AVestern district are all provided with convenient outfits for deter- 

 mining in the field the amount of carl)onates, bicarbonates, chlorids, 

 and, indirecth', sulphates. 



Tt has been found that an exceptionally large amount of gypsum 

 was carried by some of the irrigation Avaters of the AVest and was held 

 in solution in the soil moisture. This Avas found to be due to the 

 presence of sodium chlorid and other salts. The mutual effect of 

 these salts on their solubility in Avater, in solutions of all concentra- 

 tions, had to be Avorked out in the laboratory for the interpretation 

 of certain phases of the alkali j)roblem. In this connection, a paper 

 was published in Report Xo. 64 on the nature of solutions as applied 

 to the study of soil problems. Another matter Avhicli received some 

 attention Avas the formation of sodium carbonate or Ijlack alkali by 

 certain saltbushes, commonly found in the West. The results of this 

 inA^estigation, shoAAing that sodium carbonate is found in the decay 

 of certain plants, Avill shortly be published. 



The role of carbonic acid in soil solutions as affecting the various 

 soil constituents has been iuA^estigated, and is still the subject of 

 extended studies. Much of the work is being done conjointly Avith 

 tlie i^hysical laboratory, and the results promise to be not only of con- 

 siderable scientific interest, but of great economic importance. For 

 instance, it has been found that Avhen sodium carbonate exists in a 

 soil, or is added to a soil, a considerable portion may change to sodium 

 bicarbonate, Avhicli is probably no more harmful to A'egetation than 

 sodium chlorid or sodium sulphate. 



The subject of hardpan formation has also been iuA^estigated, and 

 some A'erj^ interesting results haA^e been obtained. This is a matter 

 of great economic importance in certain sections of the country. 



Mr. F. P. Veitch Avas detailed to this Division by the Maryland 

 experiment station, in September, 1808, for work upon the soils of 

 Maryland. Sixteen of the mostinij)ortant types of soils found in that 

 State haA-e been studied, Avith reference to their chemical constitution 

 and the relatiAe solubility of the soil constituents in different soh-ents. 

 The object of the Avork is to gain as much information as possible 

 regarding the form of combination of the constituents of the soil. 

 The Avork has not progressed sufficiently far to make any definite 

 statements, but the results so far obtained giAe great promise of a 

 most important line of work. 



TOBACCO INVESTIGATIONS. 



MucJi of Mr. Floyd's time, as toljacco expert of the Division, has 

 been taken up in the collection and arrangement of material for the 

 tobacco exhibit of the United States at the Paris Exposition. Inci- 

 dentally, a A'ery large amount of information has been acquired, 



