SULPHURIC-ACID TREATMENT OF SEEDS AND ITS VALUE TO COTTON PLANTING AND CULTURE. BY THOMAS TAYLOR, of Washington, D. C.

WHILE making some microscopical examinations about fifteen months ago, to determine the position of the oil-cells in Indian corn, I found that the germ of this seed was remarkably well protected from accidental injury. It is surrounded by a series of oilcells, outside of which are many layers of starch-cells, filled with granules of starch. Bounding these cells is a second series of oil-cells in close contact with, and under the external cellulose coating of the seed.

As one of the results of this investigation, it occurred to me that seeds of this structure might with entire safety be subjected to chemical action, with a view to effect certain chemical changes, in those outer portions which serve as nourishment to the germ, thus accelerating the process of germination. For the purpose of experiment on this point, I selected sulphuric-acid for the reason, that, like diastase, this agent has the property of converting starch and dextrine into grape sugar, substances used as plant food in the germination of the embryo.

Indian corn is a type, in its internal structure, of a large class of seeds. The cotton-seed is a conspicuous example of another class.

In the cotton-seed the entire space inside the pericarp is occupied by the embryo or miniature plantlet. This plantlet, it removed and subjected to chemical treatment, will be seen, by the aid of the microscope, to be charged with starch, oil and albumer, thus showing that the plantlet contains within itself the food necessary for its proper germination.

Owing to such differences of structure, the action of sulphuricacid is not alike on all seeds. In one case the acid may be employed to act directly on the proximate principles of the seed, while in others, as in the case of the cotton-seed, its action may be confined to the process of reducing the non-conducting substance of the hull, so that heat and moisture from without may have more ready access to the germ or plantlet.

In the cotton-seed, the benefits of the acid treatment are conspicuously manifest. The cotton-seed of commerce is covered with matted short fibres of cotton, firmly adhering to the compact woody shell or pericarp. As a result of experiment, I have found

that two ounces of strong sulphuric-acid poured over sixteen ounces of cotton-seed, as now used for planting, completely dissolves the cotton-fibre on its surface, changing it into a gummy substance soluble in water. If sufficient time is allowed for the acid to act on the hull, the latter is reduced in thickness and rendered more porous. On washing the seeds thus treated with plenty of water, the gummy substance is removed, and the seeds appear clean and smooth, resembling in color a ripe apple-seed. When the seed is thus cleaned there is no mechanical obstacle to the use of machinery in planting it, whereas it is now planted by hand throughout all the cotton-growing regions of the world; but before this advantage can be utilized by the planter, it is essential to show that the germ of the seed is uninjured by the use of the acid. If a cotton-seed, treated as above described, is immersed in water for a period of say twenty-four hours, the hull may be removed by the careful use of a knife and the leaves and pluinule of the plantlet thus exposed may be examined by a low power of the microscope.

If sufficient mechanical care has been observed in the removal of the hull, the plantlet will appear perfect in all respects, showing that no chemical injury has been sustained on its surface by means of the action of acid on the external surface of the hull or pericarp. From these and other facts thus gained by the use of the microscope, I became firmly impressed with the conviction that cotton-seeds thus treated were not only uninjured, but would germinate earlier than seeds planted in the usual manner. But to leave no doubt upon this point, I determined to test such seeds by having them planted under conditions favorable for germination; and to this end I placed them in the hands of Mr. Wm. Saunders, Superintendent of Gardens and Grounds of the Agricultural Department at Washington. I visited daily the hot-house in which these seed-experiments took place and took notes of their daily relative growth. The experiments were conducted in the following manner:—

In every experiment two samples of seed were used and placed in separate pots side by side and under the same general conditions. One lot was treated with sulphuric-acid, the other planted in the usual manner without chemical treatment.

In this way we

could judge of the acid treatment by comparison of growth. The first cotton-seeds planted were subjected to an average temperature of about 67° Fah. It was during the winter. The seeds

treated with acid germinated in about eighty-two hours, the untreated in about one hundred and sixty-four hours.

When similar experiments were made under an average temperature of 85° Fah., the treated seeds germinated in about forty hours; the untreated in about ninety hours. One sample was treated with full strength sulphuric-acid of commerce for a period of one hour. The seeds were next removed from the acid, placed on a glass-plate and allowed to remain in that condition unwashed for a period of twenty-four hours, after which they were washed in water and planted. After a lapse of thirty hours these seeds germinated, and they have produced thrifty plants which are now in bloom and partly bolled. Hundreds of cotton-plants have been successfully grown from the seeds used in these experiments; and in every case, where comparison was made, seeds treated with strong sulphuric-acid germinated earlier than those not so treated. Several persons in the city of Washingon, D. C., have planted, in open ground, treated cotton-seeds, furnished by me. All of them have germinated and produced healthy plants some of which are already bolled. My own garden furnishes several examples.

In all these experiments the seeds were planted, according to hot-house custom, near the surface of the soil. The cotton-seeds were planted about one-fourth of an inch below the surface. When planted in the field, they have a covering of about three inches of earth. Treated seeds, planted at that depth, would during high temperature germinate much earlier relatively than seed untreated; because the cotton covering and thick hull offer more resistance to transmitted heat at a depth of several inches, than they will when nearer to the direct rays of the sun.

Theoretically and, I believe, practically the planter will gain several days' time by planting treated seeds. In the process of washing, the light, inferior and wormy seeds, which float on the surface of the water, may be at once removed. The heavy and plump seeds fall to the bottom.

The washings should be saved and thrown on the home-made manure pile. The sulphuric-acid they contain will absorb the escaping ammonia and thus preserve from waste a valuable fertilizing agent.

During the past year I have made many experiments with other seeds, including cranberry, tobacco and sorghum seeds, wheat, oats, peas, beans, Australian tree-seeds and palm. All seeds,

treated by soakage in full strength sulphuric acid of commerce, germinated without failure.

Two sets of old and hard Australian tree-seeds were planted, one set having been severely treated with acid, full strength.

There was a marked difference in the time of germination between the treated and untreated seeds. All of the treated seeds germinated within one month, while the non-treated did not germinate until the expiration of three months after planting. Beans were so severely treated that their hulls separated and shrivelled up, yet all germinated and grew vigorously.

A palm-seed measuring 24 inches long by 14 inches across, and as hard as vegetable ivory, was soaked in a mixture of sulphuricacid, diluted with fifty per cent. of water for a period of twentyfour hours, and to render the soakage the more complete, the shell of the nut at the base end was removed to the extent of half an inch in diameter superficial measurement.

This seed germinated three weeks after planting, although the usual period of germination of the seed under hot-house culture is sometimes several years. Seeds which ordinarily germinate in a short period of time are not improved by the acid treatment, as far as my experiments have gone. Its utility has been most conspicuous in the case of cotton-seeds and hard and old tree-seeds, including palm-seeds.

It is my present purpose to continue my experiments with seeds, and any useful results that may be attained will be made known to the public in the Reports of the Department of Agriculture or other publications. In the meantime, it is my intention to have treated cotton-sceds tested in the open fields in the coming season on a scale sufficiently large to ascertain practically the benefits of the sulphuric-acid treatment.

The following extract from a letter from a practical cotton planter, formerly of North Carolina, sets forth clearly the possible advantages to be derived by the planter from cotton-seeds thus treated:

MR. THOMAS TAYLOR,

WASHINGTON, D. C.

24th July, 1880.

Microscopist, Department of Agriculture.

DEAR SIR:

I know something about the raising of cotton, having spent the greater part of my life in Cabarrus County, North Carolina, where cotton is our money crop.

Your discovery of removing the lint from cotton-seed without injuring the germ is of great value.

In the first place: as you prepare them, the seed can now be drilled at regular intervals apart, as easily as grains of corn, and this will, to a great extent, if not entirely, do away with the labor of thinning out the weed known among planters as "chopping cotton." This regular drilling was not possible by any machine while the seed was coated with lint, for the lint held the mass together, so that the individual grains could not be separated.

In the second place: the seed, as you prepare them, come up much earlier than what we may now call "lint-seed."

This makes them doubly valuable to the planters of the Northern belt of the cotton region, where the frost so often catches the crop, cutting it down, not unfrequently one-third. The earlier start of the prepared seed will much reduce the damage now done by the frost.

Yours truly,

WM. M. COLEMAN.

PERMANENT MICROSCOPIC PREPARATIONS OF PLASMODIUM. By SIMON H. GAGE, of Ithaca, N. Y.

THE previously published methods of making permanent preparations of the motile or naked protoplasmic stage of the Myxomycetes are but two, so far as I know; and no method of getting the Plasmodium in a desired position has to my knowledge been published.

The old method was to dry the extended Plasmodium, the new is to harden it with osmic acid. Both these methods are defective, for osmic acid changes the color of the protoplasm, and drying causes it to shrink as well as to change color.

The following is a simple and efficient method of extension and preservation: Small pieces of the rotten, wood, on which the Plasmodium is found, should be placed on moistened microscope slides with some of the Plasmodium touching the slides. These should be on a piece of window or plate glass, and over the whole should be placed a bell-jar, or other cover, to prevent evaporation. After an hour or more, the glass on which the slides rest should be lifted up to see whether the protoplasm has crawled out upon any of the slides. If any of the slides are satisfactory, lift off the bell-jar and remove the pieces of wood from the slide. The