NOTES FROM THE U. S. BUREAU OF CHEMISTRY.*

COMPOSITION OF THE ASH OF SPANISH MOSS.'

By Edgar T. Wherry and Ruth Buchanan.

IABSTRACT.]

T~tE Spanish moss is an epiphyte, but not a parasite. The scales with which it is covered probably do not act to retard transpiration, but to hold water by capillarity while the plant is absorbing mineral constituents therefrom. Samples were collected from the seacoast in South Carolina and from far inland in Georgia, and the compositions of their ash determined, both with and without washing. A sample of Beard-lichen from Maine was also analyzed for comparison.

The analyses of washed and unwashed samples showed some differences, but these were not systematic and gave no indication that the washing removed adherent dust. The Spanish moss proved to be unusually high in soda, ferric oxide, sulphur, chlorine and silica. The chlorine was somewhat higher in the seacoast plant, and although the sodium was lower, this was connected with a much higher content of ferric oxide, diminishing all the other bases proportionately. Consideration of the composition of rain water shows that in general this plant does not take up constituents in the proportions present in the water, but exerts a marked selective action.

TOXICITY OF DIPYRIDYLS AND CERTAIN OTHER ORGANIC COMPOUNDS AS CONTACT INSECTICIDES. 2

By C. H. Richardson (Entomology) and C. R. Smith (Chemistry).

[A~STRAC'r. 1

A Cl~UDW oil containing several isomeric dipyridyls and other substances was prepared from pyridine and sodium. The physical properties and chemical relationships of the dipyridyls were deter- mined and their similarities to. pyridine and nicotine studied.

In spraying experiments with six species of aphids, this crude. * Communicated by the Chief of the Bureau. 1 Published in Ecology, 7, July, I926 , pp. 3o3-3o6.

Published in Jour. Agri. Research, 33, Oct. i, I926, pp. 597-6o9.

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