132 EXPERIMENT STATION RECORD. 



According to the authors, in the burning of organic compounds the destruc- 

 tive distillation carbon-bearing gases, CO, C2H2, C2H4, and CHi, are not generally 

 completely burned and may be the source of injui"y in the smoke. Experiments 

 with sweet pea seedlings show that smoke from cigarettes, cigars, and cellulose 

 paper does not contain sufficient CO, C2H2, or CHi to amount to 1/200 of the 

 toxicity of the smoke. This leaves CjH* as the substance probably determining 

 the toxicity. 



The injury from smoke in cities is usually attributed to sulphur dioxid and 

 sulphur trioxid, so far as gases are concerned. The authors claim that the 

 possible effect of the dry distillation of carbon-bearing gases has been neglected, 

 and that on account of their extreme toxicity they are probable factors in the 

 smoke question. 



A delicate test seedling', W. Ckockeb, L. J. Knight, and R. C. Rose {Abs. in 

 Science, n. ser.,.31 (1913), No. 949, pp. 380, 381).— The investigations of the 

 authors have shown that ethylene gas produces with sweet pea seedlings what 

 is termed a triple response, marked by a reduction in the rate of elongation, 

 increased growth in diameter, and diageotropism. The effect of some 50 or 

 more gases and vapors upon the seedlings has been studied, and the seedlings 

 found apparently reliable and extremely delicate in testing for ethylene, being 

 from 2,000 to 5,000 times as delicate as gas analysis methods. While other gases 

 give the triple response, they must be present in such quantities as to be easily 

 detected by other means. 



Formaldehyde in the sap of green plants, F. Angelico and G. Cataxano 

 (Oaz. Chim. ItuL, .',3 (.1913), I, No. 1, pp. SS--'/5).— Experiments bearing upon 

 the hypothesis that formaldehyde is formed in light directly from carbon dioxid 

 and water were carried out with the leaf sap of Lupinus albus, Becurigera 

 coronilla, Lathyrus gorgonia, Mii-aMUs jalapa, Dolichos albiflorus, Lavatera 

 olMa, Helianthus annuus, Alcebia quinata, Zea mays, Mesembryanthemum cordi- 

 folium, and Tropceolum majus, all of which after normal illumination gave posi- 

 tive response to tests for formaldehyde. The first six of these, after having 

 been kept for 24 hours in darkness, gave negative reactions, as did also Psalli- 

 ota campestris, CUtocybe sp., and Coprinus sp. It is held to have been shown 

 that the formation of formaldehyde in green cells depends upon the factors 

 chlorophyll and light, and that it bears an intimate relation to photosynthesis. 



Conditions affecting the development of lycopin in the tomato, B. M. 

 DuGGAR (Abs. in Science, n. ser., 37 (1913), No. 9Jf9, p. 37S).— The author states 

 that both lycopin and carotin occur in the ripening of the tomato. An experi- 

 mental study of the effects of various conditions upon ripening demonstrated 

 that while cai-otin is developed under conditions of growth differing quite widely, 

 lycopin is formed only within a limited, range of metabolic activity. Tempera- 

 ture and oxygen supply are two of the factors indirectly limiting lycopin devel- 

 opment. In yellow varieties of the tomato carotin only is found, while in the 

 red varieties the formation of lycopin is precluded by high temperatures, yellow 

 fruits resulting. Irreversible effects are not produced by heat. Red tomatoes 

 are believed to contain a factor for i-edness superimposed upon the factor or 

 factors for yellow, and this conclusion is borne out by breeding experiments. 



The reg'ulatory formation of tannase in Aspergillus niger and Penicillium 

 sp., L. Knudson (Abs. in Science, n. ser., 31 (191,3), No. 9.'i9, p. 378). — Tbe in- 

 vestigations of the author have shown that A. niger, P. riiguJosum, and Penicii- 

 lium sp. can ferment tannic acid, gallic acid resulting. Experiments were con- 

 ducted by him with 14 organic compounds used as sources of carbon, but only 

 when the source of carbon was tannic acid, gallic acid, or cane sugar supple- 

 mented by gallic or tannic acids were the organisms able to form tannase. Gallic 

 acid was not as efficient as tannic acid in stimulating the production of the 



