650 EXPERIMENT STATION RECORD, 



U'iOl). — The author claiius that ])iitas8inni tetroxahite of constant composition can be 

 prcpareil from oxahc acid whicii lias ])cen carefully jjurilied ])y crystallization (from 

 hot hydrochloric acid and boiling water), by recrystallizing the tetroxalate obtained 

 on adding potash solution to the oxalic acid, jiressing between sheets of hardened 

 filter paper, and allowing to air-dry until the crystals no longer adhere to the sides 

 of a glass vessel. It is pointed out that the dilticulty which has often been encoun- 

 tered with this reagent was probably due to the fact that the tetroxalate was prepared 

 by desiccation over sulphuric acid. 



On tlie titration of sulphuric acid with, benzidine hydrochlorate, W. J. 

 Mui.i.Eij and II. Di'RKKs (Ztsrhr. Aiuilyt. Cherii., 4'-^ {1903), pi>. 477-492; ahs. in Chem. 

 CcnihI., 1903, II, Xo. 17, pp. 904, 9()')). — The investigations reported are a continua- 

 tion of previous work (E. S. R., b5, p. 337) and relate to conditions of accuracy and 

 applications of the method to various compounds. 



On the impurities in compressed oxygen and their role in combustion by 

 means of the bomb calorimeter, ]\I. Berthelot {Ann. Chim. et Phys., 7. ser., SO 

 {1903), Axg., pp. 43.3-440, fiy. 1). 



The determination of carbon dioxid, A. Wohl {Ber. Deut. Chem. Gesell.,-36 

 {1903), pp. 1412-1417; abs. in Bui. Soc. Chim. Paris, 3. ser., 30 {1903), No. 22, p. 

 1230). — The method described is based upon the loss of weight due to the expulsion 

 of carbon dioxid, aqueous vapor generated within the flask being used for the latter 

 purpose. The apparatus employed and the precautions observed to prevent inaccurate 

 results due to altsorption of carbon dioxid ])y condensed a(iueous vapor are de.scribed. 



The determination of argon in atmospheric air, H. Moissan {Compt. Rend. 

 Acad. >Sci. Paris, 137 {1903), No. 16, pp. 600-606). 



On the determination of the composition of chemical compounds without 

 the aid of analysis, G. Tammann {Ztschr. Anorgan. Chem., 37 {1903), No. 2, pp. 

 30-3-313, figs. 6). — The method described is based upon the melting or fusing point 

 and the relation of the properties of the crystallized fusion to chemical composition. 



The general principles of physical science, A. A. Noyes {New Yorlc: Henry 

 Holt & Co., 1902, p)p. VII +172; rev. in Science, n. .ser., 19 {1904), No. 472, p. 102). 



The progress in agricultural chemistry, 1902, A. Hilger, T. Dietrich, et 

 AL. {.Tuhresher. Agr. Chem., 3. ser., 5 {1902), pp. XXXVI + 580).— Thia contains 

 abstracts of the more important articles in agricultural chemistry j)ublished in 1902, 

 and titles of articles of less imijortance. The subjects are classified, as usual, under 

 plant production, animal production, agricultural technology, and methods of 

 investigation. 



BOTANY. 



Acidity of plants, A. Astruc {Ann. Sci. Nat. BoL, S. ser., 17 {1903), pp. 1-108; 

 abs. in Jour. Roy. Hort. Soc. [London'], 28 {1903), No. 1-2, j)p. 229, 230).— An account 

 is given of investigations on the occurrence of free or partially combined acids in 

 different plants, and in different parts of the same plant under varying conditions. 



In the case of nonsucculent plants the chief conclusions drawn are that vegetable 

 acids are present in greater quantity in young leaves and diminish as the leaves 

 become older, and that the younger parts of the leaf contain more acid than the 

 more mature parts of the same leaf. The organic acids are gradually fixed Ijy satu- 

 ration or etherification and disappear as free acids. The production of organic acids 

 is intimately associated with the processes of respiration and assimilation. In the 

 green parts of variegated leaves the acids are more abundant than in the paler parts, 

 and in etiolated i)lants the acids increase on exposure to light. In the stem the 

 greatest acidity is found in the young growing parts. The acidity of the flowers 

 decreases as development goes on, but begins to increase as the flowers begin to 

 fade. This change is said to be due to the commencement of the growth of the 

 ovary into fruit. 



