1052 EXPERIMENT STATION RECORD. 



present in quantities of 4 :100 the coloration appears in a few minutes; when present 

 in amounts of 4 : 1,000,000 the coloration appears in about 2\ hours. Salicylic acid, 

 benzoic acid, hydrogen peroxid, and other preservatives tested gave no color reaction. 



Concerning the estimation of fluorin in wine and beer, F. P. Treadwell and 

 A. A. Koch (Ztschr. Analyt. CJiem., 43 (1904), No. 8, pp. 469-506, figs. 2).— Different 

 methods of estimating fluorin were critically studied with a view to finding a satis- 

 factory method. 



The colorimetric estimation of salicylic acid in foodstuffs, F. T. Harry and 

 W. R. Mummery {Analyst, 30 (1905), No. 349, pp. L.'4-127).—ln order to obviate the 

 difficulties experienced in obtaining a good color with ferric chlorid in foodstuffs 

 containing tannin the material is treated with basic lead acetate, when the lead sali- 

 cylate formed, being readily soluble in caustic alkalis, may be separated from the 

 insoluble lead tannate. 



BOTANY. 



North American species of Agrostis, A. S. Hitchcock (U. S. Dept. Agr., Bureau 

 of Plant Industry Bui. 68, pp. 68, pis. 37, figs. 2). — This bulletin presents the descrip- 

 tion of 27 species of Agrostis found north of Mexico, together with a list of species 

 excluded and notes on Mexican species. The classification and history of the species, 

 as well as the history of the genus is discussed. The generic description and a key 

 to species are also given. 



Notes on plant transpiration, A. Dulov ( Trudui Opuiln. Lysn., 1904, pt. 2; <ihs. 

 in Zhur. Opuitn. Agron. [Russ. Jour. Expt. Landw.], 5 (1904), No. 5, p. 707).— The 

 author undertook the study of transpiration in connection with the new growth of 

 pure maple and ash plantings. With this object in view, he examined the humidity 

 of the soil in both plantations and determined the amount of precipitation and the 

 evaporation during the period under investigation. 



From the data secured the author endeavored to ascertain the amount of moisture 

 received by the trees from the soil and expended by them for the formation of the 

 organic matter of that year. He found the transpiration coefficient of maple to be 

 289 and that of ash 399. Notwithstanding the greater evaporation of the ash the 

 latter, according to the author, more successfully resists drought than the maple. 

 This was strikingly demonstrated by the observations in the spring of 1903, when 

 owing to a drought during the preceding fall and a small amount of precipitation dur- 

 ing the winter and spring almost all maples died, while the ash trees continued to 

 develop quite normally. — p. fireman. 



The transpiration of sun and shade leaves of the olive and other broad- 

 leaved evergreens, J. Y. Bergen (Bot. Gaz., 38 ( 1904), No. 4, pp. 285-296, figs. 11) . — 

 The morphological and histological differences of shade and sun-grown leaves of 

 various kinds are shown, and an account is given of the relative amount of transpi- 

 ration from leaves produced under the different conditions. 



The experiments show that under normal conditions for each class of leaves sun 

 leaves transpire from 3 to 10 times as much as shade leaves of the same species. 

 Under abnormal conditions with both classes of leaves the sun leaves of the species 

 studied transpire more than 1 J times as much as the shade leaves. The thinnest 

 and most poorly nourished shade leaves contrast much more sharply with sun leaves 

 in their behavior than do the more normal leaves which are developed in the shade. 

 Shade leaves exposed for some hours to full sunshine may become almost unable to 

 transpire without showing any evidence of wilting. 



The relative transpiration of old and new leaves, J. Y. Bergen (Bot. Gaz., 

 38 (1904), No. 6, jjjj. 446-4S1). — While making studies on the transpiration of coria- 

 ceous evergreen leaves, the author became interested in the subject of the relative 

 activity of old and new leaves. The studies were made on the shores of the Med- 

 iterranean, where trees and shrubs are largely evergreen, but the author limits the 



