METEOROLOGY. 613 



The determination of ammonia nitrogen in steer's urine, D. C. Cochrane 

 {Jour. Biol. Chcm., 23 {1915), No. 1, pp. 311-316).— Afi the result of his studies 

 the autlior concludes that " figures for nitrogen as free ammonia in the urine 

 of cattle are unreliable because of the decomposition of ammonium carbonate. 

 Figures for total ammonia nitrogen are worthless unless special precautions are 

 taken to overcome the rapid ammoniacal decomposition. Chloroform and 

 toluene fail to prevent the breaking up of the nitrogenous compounds. Sul- 

 phuric acid when added to the urine of a steer in sufficient quantity to fix the 

 ammonia present as carbonate and to slight excess retards decomposition to 

 such an extent as to allow time for analysis. All ammonia determinations must 

 be made on daily samples of urine because the sulphuric acid does not completely 

 stop decomposition in a composite sample." 



A method for the quantitative determination of lactic acid in urine, J. 

 ScHNEYER {Biochem. Ztschr., 10 (1915), No. 3-4, pp. 294-208).— A method for 

 the quantitative determination of lactic acid, based on the fact that carbon 

 monoxid is liberated when the material is treated with concentrated sulphuric 

 acid, is outlined in detail. Oxalic and aceto-acetic acids interfere with the 

 accuracy of the procedure and must, therefore, be removed, the former by pre- 

 cipitation with calcium chlorid, and the latter by boiling with acid, which con- 

 verts it to the volatile acetone. One molecule of lactic acid liberates one mole- 

 cule of carlion monoxid in the reaction, so that the quantity of acid is easily 

 calculated from the volume of gas liberated. 



The estimation of lipoid and acid-soluble phosphorus in small amounts of 

 serum, I. Greenwald (Jour. Biol. Chcm., 21 (1915), No. 1, pp. 29-36). — The 

 author has described a method for the estimation of lipoid and acid-soluble 

 phosphorus ifi small amounts of serum, in which he has combined the Neumann 

 method of oxidation and the Pouget-Chouchak colorimetric method (E. S. R., 

 26, p. 40G) for the estimation of the phosphorus. The procedure is deemed 

 probably applicable to other tissues. 



METEOROLOGY. 



Variation in minimum temperatures due to the topography of a mountain 

 valley in its relation to fruit growing, L. D. Batchelor and F. L. West ( Utah 

 Sta. Bui. IJfl (1915), pp. 26, figs. i6).— This bulletin reports the results of a sys- 

 tematic study of temperature variations in a representative area of 15 square 

 miles in Cache Valley where the elevation ranges from 4,428 to 4,901 ft. The 

 observations were confined to the cultivated bench lands on the east side of 

 the valley and valley bottoms, the entire area having a general westerly slope. 



It was found that " fruit sections located at the mouth of a canyon experience 

 a higher minimum temperature on the average than localities of similar eleva- 

 tions which are out beyond the influence of the canyon breezes. This differ- 

 ence is increased with velocity of the canyon breeze. 



"The low bottom lands of nearly the same elevation in a mountain valley 

 vary somewhat in the minimum temperatures experienced due to topography 

 of the locality ; as a whole, however, these districts are subject to a minimum 

 temperature of only small variance if the opportunity for air drainage is 

 similar. Localities of similar slope and elevation along the bench lands, and 

 with equal chance for air drainage, experience nearly identical average mini- 

 mum temperatures. A small difference in elevation may be somewhat equalized 

 by a difference in the opportunity for air drainage. The minimum temperatures 

 experienced by the bench lands, and upper slopes of the tillable area in a 

 mountain valley average from 6° to 10° F. warmer than the valley bottoms, 



