118 



JOURNAL OF THE 



hand and put through a 60 mesh sieve. The fine earth (that 

 passed the sieve) alone was used in the analysis and experi- 

 ments. (See Table V). 



The names of the varieties of soils below were given as sug- 

 ted by Boussingault,* dependent on actual contents of the 

 various ingredients, and were : 



1. Sandy, with little Clay. 



2. Stiff Clav. 



4. Sandy, with Humus. 



5. Clayey Sand. 



table v. 



SHOWING ANALYSES OF SOIL- 



Each mixture consisted of 1 gram acid phosphate and 4 grams 

 of the soil, and was carefully and thoroughly intermixed and 

 stirred to a thick paste, by the addition of a few cubic centime- 

 tres of distilled water. A short glass rod was used for this pur- 

 pose, which was allowed to remain in the mixture. The vessel 

 containing the mixture was a small cylindrical glass jar, 50 mm. 

 in diameter and 62 mm. high. Sixty-four of these mixtures, 

 representing sixteen sets of each of the four varieties of soils, 

 were prepared at the same time, each containing 1 gram of acid 

 phosphate and 4 grams of soil. Each of the jars, covered with 

 a small glass plate, was placed on one of a series of shelves in a 

 covered wooden box about 12 inches square aud 12 inches high. 



A thermometer inserted in the box registered a mean temper- 

 ature of 20° C. ; the extreme variation during the whole time, 

 '11 weeks, was 18°-24°, which was about the heat of the work- 

 ing laboratory. 



*Rural Economy, Translated by Law, p. 226. 



