When the University was reorganized in 1866, he was elected Professor of Chemistry, which title was changed to that of Professor of Experimental and Agricultural Chemistry in 1871. (It was the writer's good fortune this early to have become a member of his first class, in which a mutual friendship and loyalty began that continued up to the time of his death, a period of fifty years.) In the laboratory he continued his studies into the chemical and physical properties of soils in their relation to crop production, and established a small farm for culture experiments.

Although he relinquished the position of state geologist to another, he continued his interest in the further study of the geology of Mississippi and other southern states, or as he termed it "The Mississippi Embayment." In 1867, at the request of the Smithsonian Institution, he made an examination of the Mississippi river delta, the rock-salt deposit of Petit Anse Island, Louisiana, and the cause of the formation of the great mudlumps that rise in the Passes near the mouths of the river and greatly interfere with navigation. He later made a geological reconnaissance of Louisiana for the New Orleans Academy of Sciences.

Professor Hilgard, in Mississippi as afterward in California, was always full of energy and activity in and out of the laboratory, working in the interest of the University, the state and especially the farmers; with the latter he was in close touch, advising and aiding them as far as possible in their difficulties, and he was regarded by them as a true friend. He was the first to analyze the cotton lint, oil, hulls and seed cake and to point out the loss which the farmer sustained by his habit of putting the whole seed on the land instead of having its valuable oil (which has no fertilizing value) expressed and sold and the cake alone used as a fertilizer. Professor Hilgard displayed quite an inventive genius in the laboratory, as was shown in his elutriator wheich he designed and made in the Mississippi laboratory for the mechanical separation

of soil particles. In it the flocculation or coherence of the particles suspended in the water column was prevented by a stirrer, the motive power being the works of an old clock to which was attached great weights which had to be wound up every morning by a strong negro janitor; water or electric motors were not to be had in those days.

In 1873 Professor Hilgard accepted the professorship of Geology and Natural History in the University of Michigan, but found no opportunity for research work in his favorite soil studies. While his associations there were delightful, he evidently longed to get in touch again with soil crucibles, beakers, funnels, soil solutions, and soil problems, for when, in 1874, the Regents of the University of California asked him to deliver a course of lecttures and to accept the position of Professor of Agriculture in that institution, he visited the state and gave the lectures; and seeing in California a more congenial climate and a splendid opportunity for new achievements in a new field of study, he consented to accept the position, and came to Berkeley early in 1875. He thus entered upon the field of his greatest activity in soil investigation, though greatly handicapped at the beginning by lack of facilities and by absence of interest in the department on the part of farmers and students, as well as by a spirit of "Do sit still, draw your salary and say nothing" on the part of those who should have come to his support. He protested against inactivity, and by the exercise of the same tact and perseverance and by the influence of his own enthusiasm and personal magnetism that won for him in Mississippi in 1858, he broke up the apparent indifference; a class consisting of Messrs. Christy, Edwards, Slate, and Soulé (each of whom afterward became a member of the University faculty) was recruited from other departments, and formed his first California class in agriculture; he also had a class in botany. A small tract of land was given him on which was established, in 1875, the first experiment station in the United States.

By correspondence and by visits to farmers' granges and meetings of farmers where he talked to them freely on farm topics, and by his readiness to respond to calls for information, he won their confidence and secured their co-operation in his work; and thus forty years ago he laid the foundation for the College of Agriculture that now in usefulness and in the scope of its activities is second to none in the United States.

During the thirty years in which he was director of the station he was constantly in receipt of inquiries on all subjects, not only from farmers, but from persons of other professions and even of no profession at all. He was, however, possessed of a remarkable store of information and was always ready to give freely of it to any one, as is shown by the forty or more letter books in which are preserved copies of upwards of 20,000 letters written by him in reply to such inquiries. His replies were always in full, and these forty volumes have a wealth of valuable information stored between the covers.

Prior to 1890 he established several outlying substations for the study of soil and culture problems peculiar to the several agricultural divisions of the state which are marked largely by differences in climatic conditions. The most important of these was the one at Tulare in the San Joaquin Valley, established for the purpose of studying alkali problems, in which he took special interest and pride.

Among his California activities there stands out prominently his studies on humid and arid soils, in which he was the first to point out their differences in depth and in physical and chemical characteristics; he was the first to explain endurance of drouth by culture crops in arid soils and why sandy soils are among the most productive in the arid region and the least so in the humid. He was interested not only in the soils of the United States, but in those of foreign countries and was constantly on the alert for new data.

His successful researches into the cause and occurrence of alkali salts, their effect on vegetation and especially the methods to be used in their neutralization and the reclamation of the land in which they occur, are well known. He was the first to enter this field and the results of his experiments have been extensively quoted and his bulletins published in other countries where alkali lands exist.

His report on cotton production in the United States made for the Tenth United States Census at the request of General Francis A. Walker, Superintendent, is also a valuable contribution to soil literature, comprising as it does a description of the geology, topography, climate, soil regions and soils of each of the cotton-producing states, (including California), as a whole and by counties, also methods of cotton culture, cotton-seed industries, cottonfibre measurements, etc. Professor Hilgard had the direction of the whole work and wrote the general part and the special descriptions of Mississippi, Louisiana and California; those of Alabama and Florida were written by Dr. E. A. Smith; Virginia and North Carolina by Professor W. C. Kerr; South Carolina by Mr. Harry Hammond; Tennessee and Kentucky by Dr. J. M. Safford; and Georgia, Texas, Arkansas, Indian Territory, and Missouri, by Dr. R. H. Loughridge. Each report was accompanied with colored maps, and by many chemical analyses of soils with discussion of results.

While Professor Hilgard was not the first to make a soil survey or a chemical analysis of the soil, he was the first to interpret the results of analyses in their relation to plant life and productiveness. He was also the first to maintain that the physical properties of a soil are equal in importance to the chemical in determining the cultural value.

In an unpublished manuscript he says: "Soils are, generally speaking, the most complex materials commonly coming under investigation, and the most difficult to interpret in the relations with vegetation; the latter being,

in the end, the final result aimed at. Soil study claiming completeness necessarily involves not only the chemical and physical examination of the material, but also its geological nature, position and derivation; the latter implying the determination of its mineralogical components not only for the sake of indications of its derivation, but also its probable general chemical nature. Moreover, the observer will most commonly find all changes of soil worthy of being shown on the map, indicated by corresponding changes in the character of the native vegetation; and the latter, being the result of secular coadaptation of soils and plants, will when properly interpreted render most important service in indicating certain peculiarities, both physical and chemical, which have a very direct bearing upon the cultural character and value of the lands under investigation. It need hardly be said that all cultural experience actually had on similar land should be gathered and recorded as a specially important part of the information sought in soil survey."

Professor Hilgard tried for many years to secure funds to prosecute a soil survey of California, and his failure was a great disappointment. From information obtained through numerous short trips, from Farmers' Institutes, and from other sources a large map was prepared, showing in colors the chief agricultural regions of the state, thus excellently fulfilling its purpose; it was placed on exhibition at the Paris, Chicago and St. Louis expositions.

In the summers of 1881-83, he conducted the agricultural division of the northern transcontinental survey in the state of Washington.

The mind and hand of Professor Hilgard were never idle and, while engaged in solving old problems in relation to soil fertility and plant life, he was ever on the alert for new ones. The results of his activity are shown in the hundreds of published articles in the experiment station reports, outside journals both foreign and domestic, government publications, etc. In 1906 he published his large