310 



The writer claims that the investigation proves that under favorable 

 circumstances atmospheric nitrogen may be converted by quicklime 

 into nitric acid, and thus made available for the use of crops. It remains, 

 however, to be determined what are the peculiar circumstances under 

 which this favorable action takes place. An inspection of the above 

 figures will show the large amount of chlorine and the comparatively 

 small proportion of soda in the cultivated soil. This chlorine must have 

 been derived from the sea-spray, and was therefore originally in the form 

 of chloride of sodium, but it now exists in combination with the metallic 

 base of lime. The writer concludes that transformation of common salt 

 into chloride of calcium constitutes the condition favorable to nitrifica- 

 tion in the soil. 



Temperature of the soil. — MM. Becquerel and Edm. Becquerel 

 have published a memoir upon some observations made with the aid 

 of an electric thermometer, so arranged that the temperature of places 

 and objects at some distance from the observer may be determined. 

 These gentlemen have applied it to the determination of the comparative 

 temperatures of bare soil, and that covered with low vegetation. In 

 order to obtain the average temperature for the year the observations 

 Avere made during the last five days of August, the months of Septem- 

 ber and October, at the hours of six and nine in the morning, and three 

 and six in the evening. The averages of these results were calculated 

 and arranged in tables. 



The instrument was placed under the soil at depths of 0.05 and 0.10 

 meter, (2 and 4 inches nearly.) 



The average of the observed temperature (reduced to Fahrenheit) wa» 

 as follows : 



2 inches. 4 iuchea. 



A ^101 < Covered soil 72 71.8 



August, 1871.... jj3^j,gg^.l 79 75 



c J. 1 10-^1 ^Covered soil 65 64.8 



September, 1871. J B^^^gg^il ^ 65 



j-\ i. 1, iQ-M < Covered soil 50.5 50 



October, 1871.... J j3^^^g^il _ ^q 50 4 



The average of the morning observations, which were made at 6 o'clock 

 a. m., shows clearly the cooling effect of exposure : 



2 inches. 4 inches. 



Covered soil 68.8 69.9 



Bare soil 64.5 67.3 



„ , , (Covered soil 61 62.8 



September J Bare soil 58 59.7 



„ , , ( Covered soil 49 50. 5 



October J Bare soil 45 45.8 



From the above figures we learn that the average temperature of the 

 bare soil was 5.5 degrees higher than that covered with vegetation, but 

 the morning temi)erature of the covered soil was 3.8 degrees warmer 

 than that which was exposed. 



Carbolic acid from living vegetation. — M. Broughton, govern- 

 ment chemist attached to the cinchona plantations of Ootacamaud in 

 India, has obtained carbolic acid from the Andromida Leschmantii, a 

 plant which grows abundantly in that section. The product is less deli- 

 quescent than that obtained from coal-tar ; but the method employed 

 for obtaining it is too expensive to allow it to be placed in the market 

 against the acid produced by the usual method. 



Absorption of water by leaves. — The recent investigations of M. 

 Calliet on the absorption of water in the liquid form by the leaves of 

 plants, have led him to the conclusion that plants do not absorb moist- 



August . 



