......

80.00

65.00

60.00

75.00

For Steamships Barbarossa, Friedrich der Grosse, Königin Luise and Bremen... All other mail steamers except those mentioned Arrangements should be made with the local representatives of the company, or with the New York agents, to secure the proper reduction. The presentation of the membership card will be sufficient evidence of the right of the applicant to secure the reduced rates.

No information has been sent in regard to further reductions for round-trip tickets. Arrangements, if any, for these reductions should be made with the agents of the company. The prices given above are for the best rooms of the first class, and the Steamship Company will accord to members of the Congress the best quarters if application be made in time.

H. W. WILEY, Chairman American Committee.

ERRATUM.

The Volatility of Titanic Oxide. - Mr. W. F. Hillebrand, Washington, D. C., has called attention to an erroneous statement in the paper on "The Commercial Analysis of Bauxite."'' It is that titanic oxide is volatile under the action of a mixture of sulphuric and hydrofluoric acids. This is a mistake. There is a very trifling loss of titanic oxide when a mixture of these two acids is employed, and it arose from a misinterpretation of some notes, for which Mr. Hancock is in no wise responsible. I am obliged to Mr. Hillebrand for drawing attention to this error. WM. B. PHILLIPS.

BOOKS RECEIVED.

1. Variation in the Amount of Free and Albuminoid Ammonia in Waters on Keeping. 2. Corrosion of Aluminum. 3. Crystallized Carbon Dioxide. 4. On the Internal Structure of Gold Nuggets. 5. Contribu1 This Journal, 20, 209.

tions to the Bibliography of Gold. By A. Liversidge, Professor of Chemistry, University of Sidney, N. S. Wales. 22 pp.

Methods for the Analysis of Ores, Pig Iron, and Steel in use at the Laboratories of Iron and Steel Works in the Region about Pittsburg, Pa., together with an Appendix Containing Various Special Methods for Analysis of Ores and Furnace Products. Contributed by the Chemists in Charge, and Edited by a Committee of the Chemical Section, Engineers' Society of Western Pennsylvania. Easton, Pa.: The Chemical Publishing Co. 1898. v+133 pp. Price: cloth, $1.00; paper, 75 cents.

Animal Fats and Oils. By Louis Edgar Andés. Translated by Charles Salter. 62 illustrations. xii + 240 pp. 1898. New York: D. Van Nostrand Co. Price, $4.00.

The John Crerar Library. Third Annual Report for the Year 1897. Preparation and Application of Fungicides. Bulletin 125, Connecticut Agricultural Experiment Station, New Haven, Conn.

The Truth about Cigarettes. Papers read and discussed by The MedicoLegal Society. 48 pp. Price, 10 cents.

Bulletin No. 43. I. Soils. II. Climate. III. Water Supply. IV. Irrigation Equipment. Report from Beeville Station. April, 1897. 30 pp. Texas Agricultural Experiment Station, College Station, Brazos Co., Texas.

Bulletin No. 44. Paints and Painting Materials and Miscellaneous Analyses. July, 1897. 15 pp. Texas Agricultural Experiment Station, College Station, Brazos Co., Texas.

Administrative Report of the State Geologist from October 24, 1894, to October 15, 1896, inclusive. 45 pp. and five half-tone plates. Administrative Report of the State Geologist for the Year Ending October 15, 1897. 20 pp. and three half-tone plates. W. S. Yeates, State Geologist. Geological Survey of Georgia, Atlanta, Georgia.

A Preliminary Report on the Marbles of Georgia. By S. W. McCallie, Assistant Geologist. Bulletin No. 1, 1894. 92 pp., with numerous halftones and maps. 1894. Geological Survey of Georgia, Atlanta, Ga.

A Preliminary Report on the Corundum Deposits of Georgia. By Francis P. King, Assistant Geologist. 138 pp., with half-tones and maps. 1894. Geological Survey of Georgia, Atlanta, Ga.

A Preliminary Report on a Part of the Water-Powers of Georgia. Compiled from the notes of C. C. Anderson, Late Assistant Geologist, and from other sources. By B. M. Hall, Special Assistant. 1896. 153 PP.. with half-tones and maps. Geological Survey of Georgia, Atlanta, Ga.

A Preliminary Report on a Part of the Phosphates and Marls of Georgia. By S. W. McCallie, Assistant Geologist. 103 pp., with halftones. 1896. Geological Survey of Georgia, Atlanta, Ga.

Constitution of the New England Association of Chemistry Teachers, adopted February 19, 1898, Lyman C. Newell, President, and Irving O. Palmer, Newtonville, Mass., Secretary.

THE JOURNAL

OF THE

AMERICAN CHEMICAL SOCIETY.

EVAPORATION AND PLANT-TRANSPIRATION.

THE

BY WALTER MAXWELL.

Received April 12, 1898.

HE data which largely compose this contribution were obtained in the course of observations bearing upon the factors which enter into a system of rational and economic irrigation, and in connection with the study of certain practical questions that relate to land irrigation on the Hawaiian Islands. These data, however, have also a more purely scientific value, and may have an interest for those who are more exclusively engaged in physiological investigations.

The actual purpose of the observations which these data represent was to try to determine: first, the loss of moisture due to direct evaporation from the soil; and secondly, the relative proportion that escapes by transpiration from the sugar-cane (saccharum officinarum) during different periods of growth, and to note the meteorological and other factors which appear to control these phenomena.

The observations on soil-evaporation and plant-transpiration were made as follows: A given weight of the particular soil was put into two tubs, exactly 125 pounds into each tub. The tubs had perforated bottoms, over which a piece of linen cloth was laid before putting in the soil, in order to prevent the soil dropping through, or blocking up the holes. When filled thus with soil, the tubs were each set into a galvanized iron pan containing water, the water being kept up to a given mark or level,

which level was the point of contact between the soil in the tubs and the water in the pans. The pans were most carefully cov ered with moisture-proof glazed oilcloth, to prevent any evaporation from the pans except through the tubs containing the soil. When the tubs were set in place, water was added to each pan by means of a funnel that was inserted through the waterproof covers, and in sufficient volume to saturate the soil, whose absorptive power was 48.2 per cent. on its own weight. This was done on April 15, and on April 16 three pieces of seed-cane were planted in tub No. 2, whilst in tub No. I no cane was planted, the latter having to record the escape of water by means of the soil, and No. 2 tub the loss by means of the soil plus the growing cane.

The tubs were placed upon a veranda, having a south exposure and a strong light, but as they had to be protected against rainfall they were so located that no direct sunlight fell upon them. Near by the tubs, temperature readings were taken. The maximum and minimum thermometers gave the extremes of temperatures, and the dry-bulb and wet-bulb thermometers the indications of "humidity in the air."

It has commonly been claimed that temperature and the "relative humidity in the air" are controlling factors in evaporation. The writer, however, has believed not only that there is not necessarily a constant relation between temperature, atmospheric moisture, and the water given off from soil and water surfaces, but that there are other factors whose individual action exceeds the united influences of the factors already stated. For this reason we decided, at the time of taking the temperature and humidity readings, to determine the actual evaporation, by use of evaporators. The form of evaporator used was a small galvanized dish, one inch deep, and having a superficial area of 120 square inches. The evaporator was placed between the dry- and wet-bulb thermometers, thus having the same protection against the sun and exposure to the wind. At seven o'clock in the morning 500 grams of water were weighed into the evaporator, and at the end of twenty-four hours the weight was retaken and recorded. The water was made up again in weight to 500 grams, proceeding thus daily over the whole period of time included by the experiment. In addition to the evaporator

described, a second one, in each item exactly identical with the former, was used. This second one was placed in a barn. The large doors of the barn were kept open day and night, thus providing an ample circulation of the outer air, but no violent wind disturbance or sudden movements of the air. The purpose in this case was to have the corresponding conditions of temperature and atmospheric humidity surrounding the former evaporator located thirty feet distant, with the exclusion of the factor of wind. The data furnished by the two evaporators were taken and recorded in the same way, with the corresponding thermometer readings. With this brief description of the mode of observation, the data are now given. These are numerous and occupy considerable space, but the full statement is necessary in order to observe the wide range of variations. Two statements could be made with some advantage, from the data. The soil-evaporation and the transpiration by the cane, however, are so bound up with the meteorological conditions that we present it as a whole :