EXTRACTS FOREIGN AND DOMESTIC. 135 



Tabular view of some of the foregoing results. 



In Cotton wool. Cotton seed. Indian corn. Potatoe. 



Weight of ash, 0.0247 p. c. 3.8oCp.c. 0.9.5 p. c. 1.09p. c. 

 Essential inorganic ingredients absorbed from the soil. 

 By Cotton wool. Cotton seed. Indian corn. Potatoe, 



' Potassa, 31.09 19.40 20.87 43.59 



Lime, 17.05 29.79 9.72 10.12 



Magnesia, 3.26 trace 5.7G 3.80 



Phosphoric acid, 12.30 45.35 18.80 11.08 

 Sulphuric acid,. 1.12 1.16 trace 31.90 



Chlorine, traces traces 2 . 18 



. Potassium,.... 2.42 



One thousand pounds of each crop give of organic ingredients, 

 of the 1st, 9i lbs.; 2d, SSi lbs.; 3d, 9i lbs.; and of the 4th, 10 

 9-10 lbs. 



The proportions of inorganic matter that may be regarded as 

 most important, are — In the 1st, 64-100 ; in the 2d, 95-100 ; in 

 the 3d, 55-100; in the 4th, 85-100 lbs. 



If equal weights of cotton wool and Indian corn be taken from 

 the same area or land', the deterioration to the soil. in organic prin- 

 ciples should be nearly the same. The yam, if compared with 

 either of these crops would appear to rob the soil of a still hea- 

 vier weight of saline matter, although it is noticeable that the pro- 

 portion of phosphoric acid abstracted by it is considerably less, 

 and that no portion of it is thus withdrawn in the condition of 

 phosphate of potassa. 



Finally, under the same weights, the cotton seed removes about 

 four tanes as much of these ingredients as the yam, and six times 

 the quantity that passes oti'by the cotton wool, or the Indian corn. 

 Moreover, the proportion of phosphoric acid (the most valued mi- 

 neral constituent of a soil,) in the cotton seed is nearly double that 

 in Indian corn, and treble that in cotton wool and the yam ; where- 

 by the inestimable qualities of the cotton seed as a fertilizer, be- 

 come still further apparent. 



The following letter from Professor Shepakd to F. A. Porcher, 

 Esq., has been communicated for publication since the foregoing 

 report. 



Chaki.esto.v, April 22d, 1844. 

 To Frederick A. Porcher, Esq. 



Dear Sik — I thank you for calling my attention to the analy- 

 s of Sea-Island cotton wool, by Dr. Ure, as quoted in the valua- 

 ■le Memoir on Cotton by the Hon. W. Seabrook. It is the first 

 .;otice I ever had of any chemical examination besides my own, of 

 the ash of cotton wool, and it is proper that I should submit a few 

 remarks to your society respecting the different results arrived at 

 in the two cases. 



