24 SCIENCE BULLETIN, No. 9. 



Chromium. 



Toxicity of chromium compounds. HENRI Corriiv. (Compt. Rend., 1808, 127, 

 977-978.) Water culture experiments lend to the following toxic equiva- 

 lents : 



K-Cr 2 (S0 4 ) a Cr 2 (S0 4 ) 3 Cr 3 K, Cr () 4 K 2 Or, 0, Na, Cr 4 



1 -142. 0-5. 0-006. 016. 0-03. 0'125. 



Na<> Cr 3 7 Air.o Cr 4 Am 2 Cn> 7 



0-0064. 006. 0-025. 



Chromic acid is the worst, bichromate less harmful than chromic acid. 

 The stimulative and toxic effects of various chromium compounds on plants. 

 PAUL KOENIG. Landw. guhresb., 1910, 39, 775-91G.) A comprehensive 

 study of the action of chromium on plant life; the action of chromium salts, 

 dichromates and chroma tes in varying concentrations, either alone or in 

 conjunction with lime, PO 3 and various salts, was observed on represen- 

 tatives of numerous natural orders, both in soil and water cultures; and 

 the toxic and stimulative concentrations for each family recorded in tables. 

 The results obtained by other workers, that the higher the degree of 

 oxidation the more toxic its effect, were confirmed. 



Chromium in soil. C. J. WARDEN. (Chern. News, 63, 85.) Soil from Andaman 

 Islands. This soil from a coffee plantation contained 1-6134 per cent, of 

 chromium oxide. 



Copper. 



Copper in various parts of the vine. F. SESTINI. (Staz. Sperirn. Agrar. Ital., 

 24, 115-132.) One vine died, presumably having been watered with a 

 solution of CuSO 4 . Four samples of vine leaves not treated with CuSO 4 

 contained 0-00047 to 0-00056 to 0-00060 and 0-00054 per cent, of copper. 



Effect of Cu salts on the growth of the vine and on soil. BERLESE and LIVIO 

 SOSTEGNI. (Bied. Central!)., 1895, 24, 768-769.) .... When the roots 

 of a vine were allowed to grow in a 1 per cent, solution of CuSO 4 , Cu could 

 only be detected in the roots. Cu remains in the soil as oxyhydrate of the 

 basic sulphate, or as a double salt of Cu and Ca. The basic sulphate being 

 readily decomposed by CO 2 , dissolves, and is absorbed by plants. 



Toxicity of copper salts. ALEXANDER TSCHIRCH. (Ann. Agron.. 1S95, 21, 544.) 

 Contrary to what is generally supposed, copper is not poisonous to plants. 

 Whilst the sulphate, nitrate, and chloride are corrosive, plants take up 

 copper without injury from soils containing copper compounds. Haricots 

 grew better in nutritive solutions to which 0-06 per cent, of copper oxide 

 was added, than in absence of copper. Frank and Kruger (Ann. Agron., 

 1895, 21, 42) showed that the copper-lime preparation had a beneficial 

 effect on the development of potatoes. 



Poisonous effects of cupric salts on higher plants. HENRI COUPIN. (Compt. 

 Rend., 1898, 127, 400-401.) Experiments on young wheat plants lead to the 

 following toxic equivalents, which represent the minimum quantity of the 

 salt that must be dissolved in 100 parts of water to kill the plants: Cu 

 bromide 0-004875, Cu chloride 0-005, CuSO 4 0-005555, Cu acetate 0-005714, Cu 

 nitrate 0-0061. It seems ctear that the effect is due to the Cu ion. It 

 follows that the use of solutions of cupric salts as germicides is attended 

 with considerable risk. 



Presence of copper in plants, and the amount they may contain. EDOUARD 

 HECKEL. (Bull. Soc. Botau. de France, 1899, 46, 42-43.) Analysis of 

 Policarpca spirostjilis are given, showing one sample containing 30 milli- 

 grams of Cu per 1,000 grams of dry matter, whilst other plants growing in 

 soils very rich in copper contained as much as 500 milligrams per kilo. In 

 Australia the presence of Policarpca is thought to be an indication of 

 copper in the soil. The ash of the seeds of Quassia gabonensis were found 

 to contain 0-698 per cent, of Cu ; the ash of the seed without the seed coat 

 contained only 0-254 per cent. Viola calaminaria is said to contain a 

 considerable quantity of zinc; and the presence of the plant usually 

 indicates Zn in the soil. 



Pot experiments with soils containing Cu. ALB. STUTZEE. (Landwirt Sch. 

 Versuchs-Stat., 1906, 65, 285-288.) Trifolium pannonicum was grown in 

 pots containing 10 kilos of' sand mixed with garden soil. Two pots received 



