824 EXPERIMENT STATION RECORD. 



not all the acid is taken up, although the quantity of powder i.« sufficient to absorb 

 the whole amount of acid when added in small quantities at short intervals. 



The reactions of the tannic acid of tea with a number of chemicals are briefly men- 

 tioned. The molecular weights in two cases determined were 503.5 and 502. 



A comparison of the pro})erties and reactions of the tannic acid of tea with the two 

 groups of tannic acids established by Trimble show that it belongs to neither, but 

 occupies an intermediate position. 



A substance closely resembling quercitin was found to differ from it in some reac- 

 tions. This substance, which has not been named, plays no important part in the 

 manufacture of tea. 



Tea leaves also contain a glycosid which the author provisionally calls tea-glyco- 

 sid. The method of (>])taining it is descril)ed. — h. m. pieters. 



An oven for igniting the precipitate of ammonium-niagnesiuni phosphate 

 in porcelain Gooch crucibles, Schallek {ZtKchr. Aiigew. Chon., 14 {1901), No. 32, 

 pp. 80(1, 801, Jigs. 2). — An oven of the Hempel pattern to accommodate 4 crucibles is 

 described. 



The C. Fresenius-Oflfenbach distilling apparatus for the determination of 

 ammonia {Bui. Assoc. Bt'Jge Chim., 1.5 {1901), No. 6, p. 219). — This apparatus is 

 briefly described and the advantages claimed for it are stated. 



The foundation principles of chemistry — a guide for the use of agricultural 

 educational institutions. I, Inorganic chemistry, (1. Altmann {frruudria.'i der 

 Cheinii . Kill Lditfudi'tifiir den Vntirrlchl <iii hnidirirtschofilleheu Lehranstalten. Leip- 

 .s/c, 1901), 5. ret\ ,d., pp. IV \ 132, Jigs. 37). 



Agricultural chemical exercises for agricultural schools, A. Mahrenholtz 

 {Die agrikulturchemischen Vbungen an Landicirtschajisschulen. Liegnitz: Reinersche 

 Buchhandlung, 1901, 2. enl. and rev. ed., pp. 08, ill). 



BOTANY. 



The effect of vrater on the maturing of •woody stems, F. KiivEssi ( Compt. 

 Rend. Acad. Sci. Paris, 132 {1901), No. 22, pp. io'.:P-7.'?^;7).— The author claims that 

 an abundant fruiting follows a year of drought, and that a humid season is followed 

 by one of small fruit production. This is due in a large degree to the maturing of 

 the branches which carry the floral buds, and in the ripening of these branches the 

 water which they contain plays an important part. It is stated that branches arising 

 directly from the trunk or occurring in the interior of the top contain a large amount 

 of water, and as a result are poorly matured at the end of the growing season. These 

 branches suffer severely on account of the winter's cold, and as a result many are 

 destroyed, and the tree naturally pruned, it is claimed that the location of the 

 flower-bearing branches conforms to the same rule. They are most numerous on the 

 slender branches in which the water conduction is limited, on account of the distance 

 of transfer, and they are also most numerous if the V)ranch assumes a vertical posi- 

 tion, in which by the added action of gravity there is a diminution of water content. 

 In this manner the form of the tree, as well as the location of the flower-bearing 

 branches, is determined by conditions influencing the maturity of branches, and the 

 maturing of branches, as well as the numlier of flowers and fruits, depends to a great 

 degree upon the amount of water which the plant receives. 



Osmotic pressure and its role in defending living cells against cold, 

 d'Arsonval {Conipt. liend. Acad Sci. Paris, 133 (1901), No. ^,pp. <s'^-6'6).— Attention 

 is called to the extreme brittleness to which animal and vegetable tissues are subject 

 when exposed to liquid air, and also the fact that yeasts ai>d various bacteria do not 

 lose their vitality when subjected to the temperature of liquid air for several weeks. 

 This resistance, the author claims, is due to the osmotic pressure existing in the 

 yeasts. If the osmotic tension be lowered by placing the yeast or bacteria in sola- 



