The Farmer’s Magazine, 1(2): 96-98 (Feb. 1859)

Seed Steeps
Cuthbert W. Johnson, Esq. F.R.S.

The attempt to improve the germination of seed. long since engaged the cultivator's attention. Chemical philosophers soon came to their aid; but, hitherto, with but little success. It is now nearly half-a-century since Sir H. Davy was experimentalizing in this important direction. Davy soon found what others have since done-that the germination of the seed might be readily hastened by the use of particular solutions. The difficulty did not end there, however. Certain chemical substances which promote early germination, seem to produce a languid alter-growth. But, still, some rather good advances have been made. It will be useful, as spring seed-time is now close upon us, if we examine the effect produced by a few of these steeps. This inquiry will hardly be rendered less valuable by the present low value of seed corn. It is evident, indeed, that the less return we receive for our crops, the more necessary it becomes to increase their produce and to diminish the coat of cultivation.

Davy's failures even, in his seed-steeping trials, were useful; they pointed out the errors which were to be avoided. It was long after his time that the use of superphosphate of lime and certain concentrated nitrogenous mixtures was introduced. His trials in the farmer's cause were commonly more resembling the alchymicists researches of the olden time than those of modern agricultural chemists. Davy also had the disadvantage of walking over the soil too much alone: he farmed as he was wont to fish on the sunny banks of the Kennett, and the romantic German rivers, either by himself or with other chemists: he had not the advantage of exploring the highly-cultivated modern farms of our island, arm-in-arm with their skilful cultivators.

It was in recording some of his trials on accelerated germination that he told his readers (Elem. Agri. Chem., 218) that he had found several chemical menstrua which rendered the process of germination much more rapid when the seeds are steeped in them; but the result proved that the practice was inadmissible, for seeds so treated, though they germinated much quicker, did not produce healthy plants, and often died soon after sprouting. This celebrated chemist steeped radish seed, in September, 1807, for twelve hours before they were sown, in a solution of chlorine, and similar seeds in very diluted nitric acid, in very diluted sulphuric acid, in a very weak solution of sulphate of iron, and some in common water. The seeds in solutions of chlorine and sulphate of iron threw out the germ in two days, those in nitric acid in three days, in sulphuric add in five, and those in water in seven days. But in the cases of premature germination, though the plume was very vigorous for a short time, yet it became at the end of a fortnight weak and sickly, and at that period less vigorous in its growth than the sprouts which had been naturally developed. Davy thus was led to very correctly conclude that "too rapid growth and premature decay seem invariably connected in organised structures; and it is only by following the slow operations of natural causes that we are capable of making improvements. The failure of these powerful steeps with one or two root crops deterred Davy from further experiments. It was long after his time that the same acids were more successfully applied to the seeds of certain cereal grasses. In the summer of 1844 a Scotch farmer, Mr. G. Dalsiel Holm, of Drumlanrig (Trans. High. Soc., 1846, p. 316), tried the steeping of seed barley; and his experiments were reported by him to the late Professor Johnston. He used diluted sulphuric acid before sowing the seed, with a very marked effect on the luxuriance of the crop. In August, 1845, he observed in a letter to the Professor, "the difference was very marked in all the stages of growth, and in the end the quantity per Scotch acre was eight bushels more on the land sown with the steeped than in that sown with the unsteeped grain."

My readers will feel with the reporter of these trials (and the farmer never had a more zealous friend than Johnston), that this was a very curious fact—an experiment well worthy of being repeated on other soils, in other districts, and on different varieties of barley. But this experiment is not the only one made about the same time, on the effect of acid steeps on the growth of corn. In the report of the annual meeting at Munich, in 1844, of the German agriculturists, similar trials are reported made in Silesia by Tinzmann. In these, barley was steeped for six hours in sulphuric or muriatic acids diluted with forty times their weight of water about five pounds of acid per acre gave one fourth more grain and straw. Steeping in pure water gave more straw, but a very slight increase of grain. The same quantity of acid diluted with water, and sprinkled over the ground before sowing, gave very little increase. Arthur Young had long before this time arrived at the same conclusion.

When diluted with forty waters the sulphuric acid browned the outside of the grain, but did not prevent its growing well; it ought, however, for safety to be diluted with fifty or sixty times its weight of water. Tinzmann also tried the sulphuric and muriatic acids upon wheat, oat, and vetches, and upon turnips and grau seeds; and in all eases he found the steeped seeds, especially when sulphuric acid was used, do better than the unsteeped. It was on soils which bad been long in good cultivation that the effect of these acid steeps was found by the German farmer to be most observable.

Half a century elapsed from the trials of Davy, and we find another chemical philosopher in 1857 cautiously repeating and extending these important experiments. "The idea," well observes Professor Voelcker (Jour. Roy. Ag. Soc., vol. xix., p. 164), "of dressing seed with various fertilizing matters is not a new one. Several attempts of applying manure to the seed instead of to the land have been made, and the most preposterous advantages resulting from seed-manuring held out by certain men, whose interest it was to sell comparatively cheap fertilizing matters at an enormous profit. These attempts, as might have been expected, have proved complete failures. I allude to these attempts of manuring and steeping the seeds, because I do not wish to be suspected of entertaining for a moment the idea that the system of seed-manuring in based on rational principles. My sole object in engaging in the subjoined experiments was to ascertain if, by any chemical means, the germination of the turnip-seed could be promoted, end to collect additional evidence respecting the effect of ammoniacal thanures on the germination of seeds.

"With this object in view, I made the following experiments with new Norfolk bell-turnip-seed.

No.

  1. 100 seeds were soaked for 20 hours in distilled water, containing 2 per cent. of sulphuric acid.
  2. 100 seeds were wished for 20 hours in distilled water, containing 1 per cent, of sulphuric acid.
  3. 100 seeds were soaked for 20 hours in distilled water, containing 5 per cent. of sulphuric acid.
  4. 100 seeds were soaked for 20 hours in distilled water, containing 2 per cent. of sulphate of ammonia.
  5. 100 seeds were soaked for 20 hours in distilled water, containing 5 per cent. of sulphate of ammonia.
  6. 100 seeds were soaked for 20 hours in 3 oz. of distilled water and 1/2 oz, bone-ash dissolved in sulphuric acid.
  7. 100 seeds were soaked for 20 hours an 3 oz. of distilled water and 1 oz. of bone-ash, dissolved in sulphuric acid.
  8. 100 seeds were soaked for 20 hours in 1/2 oz. of distilled water and 4 oz. of Peruvian guano.

The seed prepared in this way was sown on the 16th of May, 1867, in garden-mould in flowerpots. On the same day were sown also in flowerpots—

  1. 100 seeds with 4 oz. of superphosphate, made by dissolving fine bone-dud in 50 per cent. of brown acid.
  2. 100 seeds with 1/4 oz. of bone-ash, dissolved in acid.
  3. 100 seeds with 1 oz. of bone-ash, dissolved in sulphuric acid.
  4. 100 seeds with 1/2 oz. of Peruvian guano.
  5. 100 seeds with 1/2 oz. of Peruvian guano, mixed with 1/2 oz. of soluble silica rock, finely powdered.
  6. 100 seeds with 1 oz. of sulphate of ammonia, mixed with 1/2 oz. of powdered soluble silica rock.
  7. 100 seeds, sown with 120 grs. of sulphate of ammonia and 1/2 oz. of powdered soluble silica rock.
  8. 100 seeds with 1/4 oz. of Peruvian guano.
  9. 100 seeds without anything.
  10. 100 seeds without anything.

"The flowerpots containing these 18 experiments were regularly watered every day. The soil was constantly kept in a moderately moist condition, and the result observed from time to time."

The general conclusions arrived at from the result of these trials are thus added in the Professor's report—

"It follows from these experiments—

"I would observe, however, that when fairly up, the plants manured with superphosphate grew much more vigorously than the others, and soon were twice as big as the rest. Although superphosphate does not promote a more rapid germination of the seed, it is yet extremely useful in favouring a vigorous growth of the plant, thereby bringing the crop out of reach of the turnip fly."

These experiments certainly deserve to be extended (and other chemical substances have to be tried). It is no reason against success that we do not exactly comprehend the nature of the asserted beneficial action of diluted sulphuric acid on seeds. This kind of ignorance naturally precedes almost all discoveries in agriculture. The use of lime and chalk as manures, for instance, would have been postponed to a very recent period, had the Roman and early British farmers waited for a scientific explanation of their action. When sulphuric, muriatic, and nitric acids, mixed with charcoal, were first experimentally applied by Arthur Young to barley in 1782 ("Annals of Agriculture," vol. i. p. 151, vol. iii. pp. 120-121), he had no knowledge of the action of the acids on the phosphate of lime of the charcoal—a result afterwards so well explained by Liebig. And when the great German philosopher did, sixty years after Young's trials were made, explain the result of the mixture, cautious old gentlemen shook their heads; and one of these gravely expressed his horror, in a note to one of our leading agricultural papers, at "the monstrous proposition" of applying sulphuric acid to the soil! Twenty years have not yet elapsed since this energetic tirade against the use of mineral acids on agriculture, and now more than half of the sulphuric acid of commerce finds its way into the farmer's service. We must, then, continue to experimentalize even in doubtful fields of research. Arthur Young need thus to carry on his inquiries. He always seemed actuated by the spirit of his contemporary, the celebrated Priestley, whom Davy thus so feelingly and instructively described in the introduction to his "Chemistry"— "He exposed all the substances he could procure to chemical agencies, and brought forward his results as they occurred, without attempting logical method or scientific arrangement. He possessed in the highest degree ingenuousness and the love of truth. No person ever discovered so many new and curious substances."