Influence of Lithium and Potassium Salts on Wheat. 347 The various salts were applied in solution on December 19, 1:47 grammes of the salt being dissolved in 150 c.c. (cubic centimetres) of distilled water, and sprayed over the surface of the soil by means of a wash bottle with a fine jet. Within an hour or so of the application of the lithium oxide the soil was found to have undergone a quite peculiar change; it became quite dark brown, and, by the next day, chocolate colour. This lasted right through the experiment, and the surface of the soil became quite caked with a crust that went about a quarter of an inch down. The effect of this was that when rain fell, instead of soaking into the soil, it collected in small pools on the surface, and it was found necessary to make holes in the soil, and, later on, to break up the crust so formed. Somewhat similar, but not nearly so marked, was the appearance where lithium carbonate was applied. Of the potash salts potassium carbonate alone showed this to some extent, but the oxide not at all. As regards germination, the lithium salts all showed a retarding effect, especially the lithium chloride, and the corresponding potash pots were distinctly the stronger. seeding had to be done on February 25, owing to the plants not coming up well, and to continuance of heavy rains with cold winds. The potash series came into ear first, and showed much more regularity than the lithium series, the ear especially being more evenly formed. With lithium sulphate it was noticeable that the leaves turned very brown, and with lithium nitrate the straw was very short, and the ear had a peculiar tapering appearance. When the crops were ready to cut, the length of straw and ear was recorded in each case. The harvesting began on August 20, 1901. The results are given in Table I. The produce of corn and straw is given in percentage of the produce of the untreated pots, and in each trial the average of the three pots is given. Lithium chloride, it will be seen from the figures, produced alike a shortening of the straw and a lower produce of corn and straw. This was not the case with the corresponding potash salt, though the straw here was less. These results are directly confirmatory of those of 1900. Lithium oxide, in spite of the crusting of the soil, gave increased produce and length of straw, and the same applies to potassium oxide. The sulphates of the two salts did no good, and the lithium carbonate, like the chloride, gave lower returns. Potassium carbonate, however, gave rather more corn and straw. nitrates of the two salts were remarkable in producing shorter straw but higher returns in weight of corn and straw; how far this latter is attributable to the presence of nitrogen in available form it is difficult to say, but certainly one would have The expected the straw to be increased in length here, and a higher produce to be obtained from the use of nitrate of potash (nitre). The following stand out as the main conclusions from this experiment : 1. That lithium salts, generally, retard the germination of wheat, and produce unevenness of crop. 2. That lithium chloride has a very retarding effect on the germination of wheat, and that it produces shortness in length of straw, and low produce both of grain and straw. 3. That lithium oxide has a peculiar effect on the soil, turning it dark brown, and causing it to "cake," but that the result, both as regards produce of wheat and straw, is favourable. 4. That lithium sulphate and lithium carbonate show no beneficial effects, the latter also darkening the soil and causing it to "cake" to some extent. 5. That lithium nitrate produces shortness of straw, but gives increase of grain and straw. 6. That potash salts do not retard germination or produce unevenness of crop. 7. That potassium oxide has, like lithium oxide, a marked effect on the soil, and produces increase of crop. 8. That potassium chloride, sulphate, and carbonate show no marked benefit. 9. That potassium nitrate gives increase, but does no better than the oxide. Influence of Lithium and Potassium Salts on Barley. 349 2. The influence of Lithium and Potassium Salts on Barley. A parallel experiment to that just described was carried out on barley. Practically the only differences in the arrangement were that zinc pots were used instead of earthenware, and that the experiments were in duplicate, not triplicate. The seed sown was "Standwell" barley, twelve seeds being sown in each pot on April 4, 1901, the plants when they came up being subsequently reduced in number to six in each pot. The same effects on the soil were noticed with lithium oxide and carbonate as in the case of wheat, that with the carbonate not being so marked. The lithium salts, as before, retarded germination, but they did not produce the unevenness of crop that they did with wheat, nor was there, generally, the lessening of produce. On the contrary, during the period of growth the lithium carbonate series looked the best of all, and in the end gave almost the highest produce, and more than all the potash salts with the exception of the nitrate. About August 20, 1901, the crops were ready, the length of straw and ear was recorded, and the whole harvested. The results are given in Table II. Here, as with wheat, lithium chloride produced less corn and shortened the length of straw; this was not the case with the corresponding potash salt. Again the oxides, whether of lithium or potassium, did well, increasing produce of corn and straw. The sulphates, whether of lithium or potassium, gave no benefit, but lithium carbonate proved distinctly advantageous, as did also the nitrates, alike with lithium and potassium. On the whole, the lithium salts did quite as well as the potash ones. As regards barley, the general conclusions are: 1. That lithium salts do not produce with barley the unevenness of crop noticeable in the case of wheat. 2. That while lithium chloride reduces the length of straw and gives a rather lower corn yield, and while lithium sulphate also shows no advantage, both the oxide and the carbonate of lithium, though they shorten the straw, give considerably increased yields of corn and straw, and results superior to those obtained with the corresponding potash salts. 3. That the nitrates, both of lithium and potassium, give marked increase of yield, though no greater length of straw. MISCELLANEOUS EXPERIMENTS. 1. Thick v. Thin Sowing of Wheat. The variety of wheat was "Street's Imperial"; earthenware pots were used, and seeds were sown in them on December 17, 1900, at the following rates per pot:-twenty, fifteen, ten, and five seeds respectively, the seed being previously steeped in 20 seeds sown 15 seeds sown 10 seeds sown 5 seeds sown FIG. 1.-Thick v. thin sowing of wheat. Appearances at harvest time, August 22, 1901. hot water (50°-55° C.) for fifteen minutes. Each set consisted of three pots, and the seeds were planted one inch deep. Between 70 and 80 per cent. of the seeds duly germinated. By June 1, differences between the seedings had begun to show Thick v. Thin Sowing of Wheat. 351 themselves clearly. With the thickest seeding (twenty seeds per pot), while the plants were regular in height and colour, there was a great difference in the "stooling" out. Thus, in one of these pots, out of sixteen plants only one had produced more than one stalk; in those less thickly sown the plants looked much more healthy and strong, the "stooling" out being much greater, and the plants of a better colour. For instance, where fifteen seeds per pot were sown, in most cases each plant had three stalks. Where ten seeds had been sown there were from twenty to twenty-four stalks per pot, and these looked the best of all. By about the middle of June there was observable a regular graduation in the height of the crop from the thick seeding, which was the shortest, to the thin seeding, which had the longest straw. These appearances are well brought out in the photographs then taken of the different pots (Fig. 1). The thickly-seeded lot ripened the quickest; the best looking of the series was clearly the seeding with ten seeds, the colour of this being superior, and the ears the best filled. On August 22 the measurements were taken, and the crop harvested. The results are set out in Table III. After the crop was harvested the roots were taken up, freed from the earth surrounding them, and photographed as shown in Fig. 2. From the results obtained it would appear that neither the thickest nor the thinnest seeding was the most satisfactory, and that the best return came from the seeding of fifteen seeds per pot, or 83 pecks per acre, a quantity which, in practice, after allowing for loss by birds, insects, &c., might be put at about 9 pecks per acre. During the time of growth, however, the thinner seeding, with ten seeds per pot (which might in practice be put at 7 pecks per acre) presented distinctly the best |