508 EXPEEIMENT STATION EECOED. 



obviate this difficulty. It consists of a wooden box with one side replaced by a 

 removable ground-glass plate. The source of light is a 25-candlepower incan- 

 descent lamp. Some results of experiments with and without artificial light are 

 included. 



Chemistry of tobacco. The essential oil of tobacco, W. Halle and E. 

 Pribram (Ber. Deut. Chem. Gesell., 47 [1914), No. 7, pp. 1394-139S) .—An essen- 

 tial nitrogen-free oil acid in reaction was isolated from Hungarian tobacco with 

 solvents. The amount obtained was 0.047 per cent. A hydrocarbon of the formula 

 CioHis or OiiHco, boiling point 73 to 76° C. at 20 mm., was obtained from the 

 lower boiling fractions. The oil before being submitted to distillation was 

 treated with sodium carbonate. When oxidized with potassium permanganate 

 it yielded compounds resembling terephalic and isobutylacetic acids. Isovaleric 

 acid was separated from the sodium carbonate solution used in treating the 

 original solution. 



METEOROLOGY. 



Modern methods in meteorology, D. E. Fontser^ y Riba (Mem. B. Acad. 

 Cien. y Artes Barcelona, 3. scr., 11 (1914), No. 21, pp. 18). — This is an inaugural 

 address reviewing some recent progress in methods of studying meteorological 

 problems. 



Climatological data for the United States by sections (U. 8. Dept. Agr., 

 Weather Bur. Climat. Data, 2 {1915), Nos. 5, pp. 238, pis. 2, figs. 8; 6, pp. 226, 

 pis. 2, figs. 7). — These numbers contain, respectively, brief summaries and de- 

 tailed tabular statements of climatological data for each State for May and 

 June, 1915. 



Annual report of the Iowa Weather and Crop Service for 1914, G. M. 

 Chappell (loiva Yearhoolc Agr., 15 {1914), pt. 11, pp. 747-794, figs. 2).— This is 

 " a condensed summary of the monthly and weekly bulletins issued by the Iowa 

 Weather and Crop Service in cooperation with the Weather Bureau of the U. S. 

 Department of Agriculture. . . . 



" The mean temperature for the State was 49.1° F., or 1.7° higher than the 

 normal. . . . The highest temperature reported was 109° at Centerville, Appa- 

 noose County, on July 12. The lowest temperature reported was — 31° at Iowa 

 Falls on December 26. . . . The average amount of rainfall and melted snow 

 for the year was 31.93 in., or 0.04 in. less than the normal, and 1.98 in. more 

 than the average for 1913. The greatest amount at any station was 44.11 in., 

 at Marshalltown, Marshall County, and the least amount was 23.32 in. at 

 Columbus Junction, Louisa County. The greatest monthly precipitation was 

 16.24 in. at Lenox, Taylor County, in September. . . . The average amount of 

 snowfall was 27.5 in. The greatest amount reported from any station was 50.7 

 in. at Northwood, Worth County, and the least amount was 14.9 in. at JMonroe, 

 Jasper County. . . . The prevailing direction of the wind was south. The great- 

 est velocity reported was 68 miles per hour from the northwest at Sioux City on 

 February 28. The average number of clear days was 166; partly cloudy, 102; 

 cloudy, 97, as against 182 clear days, 89 partly cloudy, and 94 cloudy days in 

 1913. More than the normal amount of sunshine was experienced." 



As regards crop production, the year was characterized by a deficiency of rain- 

 fall during the growing season. " The hot, dry weather during July and August 

 greatly reduced the yield of corn, especially in the southern counties, where the 

 effects of the drought were even worse than in 1913." 



The weather of the past agricultural year, F. J. Bkodle (Jour. Roy. Agr. 

 Sac. England, 75 (1914), pp. 117-124). — The means and extremes of temperature, 

 rainfall, and sunshine for 1914 and for long series of previous years in different 



