Abo 14 lb I'r 

 BXCHJLNG- 



Issued July 6, 



United States Department of Agriculture, 



BUREAU OP SOILS CIRCULAR No. 67. 



MILTON WHITNEY, Chief. 



1 . S. DEPARTMENT OF AGRICULTURE, 



BUREAU OF SOILS, 

 Washington, D. C., March 26, 1912. 



SIR: I have the honor to transmit herewith the manuscript of an article on Sponge 

 Spicules in Swamp Soils, by R. O. E. Davis, Scientist in Physical Laboratory Inves- 

 tigations, Bureau of Soils, and to request that this be published as Circular No. 67, 

 of this bureau. 



Very respectfully, _ . MILTON WHITNEY, 



Chief of Bureau. 

 Hon. JAMES WILSON, f "or >HE 



Secretary of Agriculture. { UNIVERSITY 



or 



SPONGE SPICULES IN SWAMP SOILS. 



By R. O. E. DAVIS, Scientist in Physical Laboratory Investigations. 



Recently a number of inquiries have been received by this depart- 

 ment concerning the cause of itching sensations produced in men 

 and work animals employed upon certain soils; especially in Georgia 

 and Florida. The trouble is experienced in working the soils of 

 certain areas, which happen in each case to be land that has been 

 drained. During dry weather the workmen suffer from a terrible 

 itching of the feet, and the feet of mules used in plowing become 

 sore and inflamed. The trouble is not so bad if the soil is worked in 

 a fairly moist condition. 



One of the places in Georgia from which a sample of soil was 

 obtained is described as an old cypress pond of 8 to 10 acres, which 

 has been drained for about 30 years. The soil is fertile and from 

 1 to 8 feet in depth. The same trouble is met on a farm in Lee 

 County, Ga., and in submitting a sample of the soil one of the field 

 workers of the Office of Experiment Stations writes: 



The soil can be cultivated only when wet, as the mules and men can not stay on 

 the land when it is dry. Shoes are ruined in one day and mules' feet are made raw 

 in the same length of time. Most of the drained land in the neighborhood is affected 

 with the same trouble and this fact deters people from undertaking work in drainage. 



Various suggestions have been made as to the cause of this peculiar 

 action of the soil, such as the presence of the hook-worm, pollen, 

 alkali, and sulphuric acid formed from the oxidation of sulphides in 



38765"- Cir. 6712 



