PHYTOPATHOLOGY.-Host relationships of the North American rusts, other than Gymnosporangiums, which attack conifers. ARTHUR S. RHOADS, GEORGE G. HEDGCOCK, ELLSWORTH BETHEL, and CARL HARTLEY. Phytopathology 8:309–352. July, 1918. This paper, which is of special interest to forest pathologists and mycologists, treats of fifty-two species of rusts attacking species of Abies, Ephedra, Larix, Picea, Pinus, Pseudotsuga, and Tsuga. With each species of rust is an abbreviated synonomy; citations of publications containing treatment of the species; a list of the coniferous host species; the names of genera bearing alternating stages, when present, of each rust; the distribution; remarks relative to important characters; and data of inoculating proof of the connection between the aecial and telial stages.

At the close of the paper is a host index in two parts, one of aecial hosts, the other of uredinial and telial hosts; and 148 citations of iterature bearing upon the subject. G. G. H.

PHYTOPATHOLOGY.-Some bacterial diseases of lettuce. NELLIE A. BROWN. Journ. Agr. Res. 13: 367-388, pls. 29-41. May 13, 1918.

The paper describes two new bacterial diseases of lettuce, one occurring in South Carolina and Virginia on lettuce grown out of doors, the other on greenhouse plants in Kansas. The organism producing the disease in South Carolina and Virginia has been named Bacterium vitians. In South Carolina, Bacterium vitians causes the lettuce stems to turn blue, then brown when seen in cross or longitudinal sections. Leaves are spotted occasionally but the stem affection is the prevalent condition. The organism isolated from diseased stems of South Carolina plants produces spots on leaves as well as brown stems when inoculated into healthy lettuce plants.

In Virginia the leaf spotting only was noted, but the isolated organism from these leaf spots will produce stem-rot readily when inoculated into the stem of healthy lettuce plants, as well as spots on leaves when it is sprayed on the leaves of healthy lettuce. The diseased Virginia lettuce had a second organism present producing spots on it, and this organism was isolated along with Bacterium vitians. It is one already known and described (Bacterium viridilividum) and the colonies isolated proved to be infectious.

It appears that Bacterium vitians and Bacterium viridilividum may be present and active in soil which is heavily fertilized with green

manure or stable manure not thoroughly decomposed, and in which the organisms of decomposition are still active. If conditions are such that the plants are kept growing vigorously, these organisms will have no effect upon them, but if bad weather conditions obtain and the lettuce plants get weakened or growth is retarded, these organisms make their way into the roots or leaves and cause disease. The treatment recommended is the use of thoroughly decomposed green manure and well-seasoned stable manure in which tissue-disintegrating bacteria are inactive.

The Kansas disease is caused by a soil organism, to which the name Bacterium marginale has been given. It produces either a marginal wilting, or a spotting and speckling of the leaves. Care in watering plants so that soil does not get washed on the leaves and proper ventilation of greenhouses will prevent the disease.

Isolations, inoculations, cultural characteristics, and descriptions of the two organisms are discussed. N. A. B.

PHYTOPATHOLOGY.-Influence of temperature and precipitation on

the blackleg of the potato. J. ROSENBAUM and G. B. RAMSEY. Journ. Agr. Res. 13: 507-513, fig. 1, tab. 3. June 3, 1918. Experiments were performed which showed that the organism (Bacillus phytophthorus Appel) producing the blackleg disease of the potato, under the winter conditions that existed during 1915-1916 and 1916-1917 in Aroostook County, Me., cannot live over in the soil or in diseased tubers that may remain there.

Comparison of weather records show that the winter of 1915-1916 was not an unusual one for Aroostook County.

The severity of the disease during the growing season is closely correlated with temperature and precipitation. A high temperature and low precipitation tend to diminish the disease, while a low temperature and high precipitation produce conditions favorable for it. J. R.

PHYTOPATHOLOGY.-A hitherto unreported disease of okra. L. L. HARTER. Journ. Agr. Res. 14: 207-211, pl. 23, figs. 3. July 29, 1918.

The author investigated a disease of the pods and stems of okra which occurred in Maryland in 1916. Infection experiments showed that several different varieties of okra were susceptible. The causal fungus was described as a new species of Ascochyta, A. abelmoschi.

L. L. H.

TECHNOLOGY.-Combined table of sizes in the principal wire gages. Bur. Stand. Cir. No. 67. Pp. 5. Jan. 17, 1918.

This table combines in one series the sizes in the American (B. & S.) Steel, Birmingham (Stubs'), British Standard, and Metric Wire Gages, arranged in order of sizes (diameters) of wires. It gives the diameter of all the gage numbers in these five systems in mils, millimeters, and inches, also the cross-sections in square mils, circular mils, square millimeters, and square inches. The table is especially useful to manufacturers who wish to determine the nearest equivalent in American or British gage sizes of wires specified in millimeters or square millimeters, or vice versa. R. Y. F.

TECHNOLOGY.-Determination of permeability of balloon fabrics. JUNIUS DAVID EDWARDS. Bur. Stand. Tech. Paper No. 113. Pp. 31. 1918.

This paper describes the various methods which may be employed for determining the permeability of balloon fabrics to hydrogen. The precise and rapid method used at the Bureau of Standards measures the hydrogen penetrating a given area of fabric by means of a gas interferometer. Data are given to show the effect upon the apparent permeability of different experimental conditions such as temperature, pressure, humidity of the gas, etc. A knowledge of the effect of these factors enables one to compare results of tests made under different conditions. The test adopted as standard by the Bureau is described. J. D. E.

PROCEEDINGS OF THE ACADEMY AND AFFILIATED

SOCIETIES

WASHINGTON ACADEMY OF SCIENCES

The Board of Managers met on September 2, 1918. Mr. WILLIAM BOWIE resigned as treasurer, on account of having been commissioned a major in the Engineering Corps, U. S. A., and Mr. R. L. FARIS, of the Coast and Geodetic Survey, was elected treasurer for the remainder of the year. A committee consisting of C. N. FENNER, C. N. COLLINS, and J. A. FLEMING was appointed to audit the accounts of the retiring treasurer. Mr. E. W. SHAW was appointed chairman of the Committee on Meetings, succeeding Dr. SWANN, who has left the city, and Dr. C. W. KANOLT was made an additional member of the Committee. The following persons have become members of the ACADEMY since the last issue of the JOURNAL: Dr. WILLIAM CLINTON ALDEN, U. S. Geological Survey, Washington, D. C.; Mr. SAMUEL SANFORD, Bureau of Mines, Washington, D. C.

ROBERT B. SOSMAN,
Corresponding Secretary.

SCIENTIFIC NOTES AND NEWS

A party of scientists has been sent by the Bureau of Plant Industry, at the request of the French High Commission, to Algeria, Tunis, and Morocco to study and advise upon agricultural conditions there. The party includes E. C. CHILCOTT, C. S. SCOFIELD, and T. H. KEARNEY.

Dr. ARTHUR L. DAY has presented his resignation as director of the Geophysical Laboratory, Carnegie Institution of Washington, to be in effect October 1, 1918, and will take up research on glass and allied materials for the Corning Glass Works in Corning, New York. Dr. DAY has been director of the Laboratory since its establishment in 1906, having been previously engaged in silicate researches at the U. S. Geological Survey in 1904 and 1905.

Mr. F. A. MCDERMOTT, formerly research chemist with the Corby Company, is at the experiment station of E. I. du Pont de Nemours and Company, at Henry Clay, Delaware.

Dr. H. C. MCNEIL, of the chemical department of the Bureau of Standards, has been appointed professor of chemistry at George Washington University, as successor to Prof. C. E. MUNROE, who is giving all his time to the work of the Committee on Explosives Investigations of the National Research Council.

Prof. F. A. SAUNDERS, professor of physics at Vassar College, Poughkeepsie, N. Y., is in Washington on leave of absence, engaged in war work at the National Research Council.

Dr. E. C. SHOREY, in charge of the division of chemical investigations of the Bureau of Soils, Department of Agriculture, has resigned to accept a position with the National Aniline and Chemical Company, at Marcus Hook, Pennsylvania.

Prof. W. J. SPILLMAN, chief of the Office of Farm Management of the Department of Agriculture, resigned on August 31, 1918, to become editor of the Farm Journal. He will continue to reside in Washington for the present.