and describes and reports tests of methods of manufacture of soluble potash salts from alunite. Data are also given regarding a working plant and process suited to the manufacture of potassium sulphate from Australian alunite, cost of treatment, use of alunite mixed with lime and of roasted alunite as a fertilizer, and utilization of the alumina by-product.

As a result of laboratory tests of various methods of treatment, the conclusion was reached that ignition and subsequent leaching and evaporation of the solution is the most likely process for adoption in Australia. The principal steps in the process recommended are as follows: "(1) Crush to about in. mesh; (2) roast in a suitable furnace alone, or, preferably, after the addition of molasses or sawdust as described above, until all soluble alumina is absent; (3) grind roasted ore to pass 40-mesh sieve; (4) treat the residue with boiling water and digest; (5) filter-press the pulp and wash with hot water; (6) evaporate the solution to obtain potassium sulphate product; and (7) dry and bag the product for sale."

It is stated that alunite is being utilized as a fertilizer in a small way in Australia by burning with limestone in a limekiln and grinding the product fine. This product, which contains 2.5 per cent potash, "has been proved efficacious where used, particularly in the growth of citrus and other fruits, and is well spoken of as a fertilizer." The opinion is expressed that there is no reason why a similar process should not be used to produce a product containing as high as 20 to 25 per cent of soluble potassium sulphate in combination with lime. "The alunite and lime would need to be ground together and heated in a reverberatory furnace until all the aluminum sulphate was decomposed and the potash rendered soluble. No escape of sulphur fumes should take place under these conditions, and the presence of the lime would be of value where the product is used direct as a fertilizer."

Detailed analytical data, a list of analyses of foreign alunites, and a bibliography of the subject are given in the appendix.

Availability of potash in some common soil-forming minerals.-Effect of lime upon potash absorption by different crops, J. K. PLUMMER (Jour. Agr. Research [U. S.], 14 (1918), No. 8, pp. 297–316, pl. 1, figs. 4).—In experiments conducted at the North Carolina Experiment Station, as pure specimens as could be obtained of biotite, muscovite, orthoclase, and microcline, ground to an impalpable powder, were treated with twentieth-normal solution of calcium bicarbonate, containing an excess of carbon dioxid, as follows: "Thirty gm. of each material and 200 cc. of the solvent were placed in 500-cc. flasks and agitated in an end-over-end shaking machine for 96 hours. At the end of this time suspended matter was allowed to settle, the solutions were clarified, and potash was determined colorimetrically, according to methods given by Schreiner and Failyer [E. S. R., 17, p. 831]. The residue was thrown on a filter and washed free of potash, after which it was again extracted as before, and the process repeated four times." For the purpose of supplementing the laboratory data thus obtained pot experiments were made with oats, soy beans, rye, and cowpeas grown on a soil which field tests had shown conclusively to be deficient in potash. The potash-bearing minerals were applied at rates of 200 and 400 lbs. per acre in combination with a basal fertilizer supplying adequate amounts of phosphoric acid and nitrogen and in comparison with potassium sulphate as a source of potash.

"The chief points brought out by this investigation are as follows: Little difference in the solubility of potash in water is found among the common soilforming minerals: Biotite, muscovite, orthoclase, and microcline. Biotite and muscovite give up considerably more of their potash to solutions of carbonic acid than do orthoclase or microcline. The order in which potash is removed by this

Biotite

, solvent is biotite, muscovite, orthoclase, and microcline. Lime as calcium bicarbonate does not increase the solubility of potash in any of the above minerals. "Pot experiments which include the growth of four crops—oats, soy bean, rye, and cowpea-that have had potash supplied in the form of minerals show that these plants can extract different amounts of this element from them. is able to produce four times the amount of dry matter of oats as microcline and 66 per cent as much as potassium sulphate. Muscovite produces nearly twice as much dry matter as orthoclase. The same general effect is caused from these carriers of potash with rye. Lime in the form of precipitated carbonate has not materially increased the dry matter or the potash removed from the soil by oats or rye. The dry matter of soy bean has been increased about 33 per cent when lime was used in conjunction with biotite. There was also a noticeably increased growth from muscovite caused by calcium carbonate. A much smaller increase was found from this material when the potash was applied as orthoclase or microcline. Lime caused the soy beans to remove more potash from the soil with potassium-sulphate, biotite, and muscovite treatments. This should not be taken necessarily to indicate that potash has been driven into solution, but that more favorable conditions for plant growth have been set up in the soil. More vigorous plants are thus produced, plants capable of removing more of this nutrient material. The results from the cowpeas were similar to those with soy beans. Slightly more potash was removed, after two years' cropping, by fifth-normal nitric acid from the pots fertilized with biotite and muscovite than from the control pots. No more potash was removed by this solvent where orthoclase and microcline had been added than from the controls. Lime does not appear to increase the solubility of the soil potash in fifth-normal nitric acid from any of the treatments."

The deterioration of lime on keeping, S. A. WOODHEAD (Analyst, 43 (1918), No. 506, pp. 161-165).—From results of investigations on the deterioration of lime under different conditions, the author concludes that, in order to store lime to the best advantage, it should be heaped in a powdered condition and left freely exposed to the air. Serious deterioration is prevented by the crust of carbonate which forms on the outside of the heap.

How often must liming be repeated? C. E. THORNE (Mo. Bul. Ohio Sta., 3 (1918), No. 8, pp. 236–238, fig. 1).—Observations on the effects of applying 1 ton of quicklime or 2 tons of limestone to corn in a 5-year rotation of corn, oats, wheat, clover, and timothy covering a period of 18 years are said to indicate that the period between limings on such soil as that at Wooster may be extended to 6 or 8 years.

Action of various fertilizers, especially manganese sulphate, on the growth of oats, L. HILTNER and G. KOBFF (Prakt. Bl. Pflanzenbau u. Schutz, 15 (1917), pp. 549–556; Zentbl. Agr. Chem., 47 (1918), pp. 15–19; abs. in Jour. Chem. Soc. [London], 114 (1918), No. 665, I, p. 150; Jour. Soc. Chem. Indus., 87 (1918), No. 6, p. 159).—The authors describe pot experiments in which oats were grown in various types of soils, some of which were treated with iron, copper, or manganese sulphates, or with sulphur, and all received guano.

"The addition of manganese sulphate caused in each case an increase in the size of the plant and in the total number of oat grains, especially in soils containing much humus. In peaty soils, the yield of oat grains was 70 times as great in the presence of manganese sulphate as in its absence. It is suggested that these remarkable results are largely due to the accelerating action of manganese on the oxidation of the guano added to the soil. The other sulphates and the sulphur experimented with produced similar but not such marked results."

Plant stimulation with nonessential elements, A. E. VINSON and C. N. CATLIN (Arizona Sta. Rpt. 1916, p. 300).—In both water and soil cultures conducted by P. W. Moore unquestionable stimulation in the growth of radishes, especially of the root system, is said to have been obtained with boric acid and potassium iodid. Boric acid is thought to give considerable promise of practical value in the culture of root crops.

Caliche [in Arizona], A. E. VINSON and C. N. CATLIN (Arizona Sta. Rpt. 1916, pp. 298, 299).—Work with caliche has been continued (E. S. R., 35, p. 511), comprising field and laboratory studies of the organic origin of the material as suggested by previous investigations.

"From its mode of occurrence caliche appears to have been formed by limesecreting organisms either in water or on surfaces that were frequently wetted with limy waters. During intervals of comparative quiet when little débris was being introduced and there was little interruption to the growth of these organisms the smooth caps [calcareous formations found near the top of the deposits] may have been laid down." Chemical evidence of the organic formstions of caliche is said to be less complete, but further work is expected to show the similarity of this material to travertines of known organic origin.

Report on commercial fertilizers, 1917, E. H. JENKINS and J. P. STREET (Connecticut State Sta. Bul. 204 (1918), pp. 871-422).—This contains the actual and guarantied analyses of 625 official samples of commercial fertilizers and fertilizing materials collected during 1917. Analyses of 28 samples of the ashes of household wastes and other materials, for the most part previously noted (E. S. R., 38, pp. 625, 626), are included.

Commercial fertilizers, E. G. PROULX ET AL. (Indiana Sta. Bul. 215 (1918). pp. 3-102, figs. 2). This reports the actual and guarantied analyses of 919 official samples of fertilizers and fertilizer materials collected during the spring and fall of 1917.

AGRICULTURAL BOTANY.

Some dynamic studies of Long Island vegetation, R. M. HARPER (Plast World, 21 (1918), No. 2, pp. 38-46, figs. 2).—During the season of 1916 the author made a study of a few easily accessible types of vegetation on the western part of Long Island, the results of which are given as regards the actual production by each type of fresh, dry, or ash material.

In dry weight Phragmites led the other forms by a considerable margin. The yield of vegetable tissue was in most cases, however, less than that produced by the average cultivated crop in average soils where fertilization is omitted. Observations regarding alpine species outside their usual habitat, W. VISCHER (Bul. Soc. Bot. Genève, 2. ser., 9 (1917), No. 7-9, pp. 462–466).—The author cites cases of plants which in regions more elevated than those to which they are accustomed are more frequently found in sunshine, whereas in their usual habitat they prefer the shade. The possible causes for this change of habitat are discussed. This tendency was not universal.

Mitochondria and the vacuolar system, A. GUILLIERMOND (Compt. Rend. Acad. Sci. [Paris], 166 (1918), No. 21, pp. 862-864).-Reviewing briefly attempts to identify mitochondria with well-known bodies in plant cells, the author points out differences which he claims to be very definite.

Studies in the permeability of the pulvinus of Mimosa pudica, V. H. BLACKMAN and S. G. PAINE (Ann. Bot. [London], 32 (1918), No. 125, pp. 69–85, figs. 5). Studies made on the pulvinus of the sensitive plant in a small quantity of water in a specially constructed conductivity cell are said to have shown that contraction is associated with an increase in the rate of exosmosis of elec

trolytes from the pulvinus. The nature of such increase is obscure, but its rate is too small to account for the sudden drop in the turgor of the cells. The loss of turgor is thought to be due to the disappearance or inactivation of a considerable portion of the osmotic content of the cells.

On turgescence and the absorption of water by the cells of plants, D. THODAY (New Phytol., 17 (1918), No. 5–6, pp. 108-113, fig. 1).—The author gives a brief preliminary and elementary exposition of the conditions which govern the equilibrium of a cell with a watery solution and with other cells, illustrating the consequences of such conditions by employing them in some cases considered important.

The conception of the water-absorbing power of plants is analyzed, and some important corollaries thereof are considered.

The imbibitional swelling of marine algæ, J. M. McGEE (Plant World, 21 (1918), No. 1, pp. 13–15).—The author tabulates the data from tests of the imbibitional swelling of Iridæa laminarioides, Gigartina exasperata, and G. mammillosa dissecta, red algæ growing on the rocks near Carmel, Cal. The imbibition of I. laminarioides indicates a high proportion of amino acids. Gigartina, however, appears to contain an agar-like substance, chiefly in mature fronds. This diagnosis is supported by the results of swelling dried material, which is said to conform to an expectancy of composition based on MacDougal's conclusions regarding the swelling of biocolloids (E. S. R., 35, p. 822; 37, p. 821), these being fully confirmed by the chemical analysis.

The relation of growth and swelling of plants and biocolloids to temperature, D. T. MACDOUGAL (Proc. Soc. Expt. Biol. and Med., 15 (1917), No. 3, pp. 48-50). The author notes the fact that the varying constitution and water relations of plants may be simulated (E. S. R., 35, p. 822; 37, p. 524) by employment of media artificially prepared from agar and albumin or albuminous derivatives or more successfully from proteins extracted from beans or oats, and presents data on the swelling of such media. The swelling is found to increase in initial velocity and total amount to a maximum between 39 and 46° C. in the mixture if salt is added and to 46° in the unsalted plates. The hydration in question constitutes 97 per cent or more of the volume increases known as growth.

The resistance of plants to wilting, F. CAVARA and ROSA PARISI (Staz. Sper. Agr. Ital., 50 (1917), No. 1, pp. 33-47).-As regards both the utilization of water and the survival of the plants, a number of which were studied, the specific values have shown great diversity.

Effect of loss of water on respiration of plants, V. I. PALLADIN and A. M. SHELOUMOVA (Izv. Ross, Akad. Nauk (Bul. Acad. Sci. Russ.), 6. ser., No. 8 (1918), pp. 801-808, figs. 2).—The authors report experiments carried on through the months of October, November, and December with potato tubers in the resting stage.

Part of this material was exposed to drying in the air at room temperature, with the result that during the first days in spite of a great loss of water the energy of respiration was gradually increased, but the further loss of water caused a distinct lowering of this energy. When the same tubers were immersed in water the respiration was again stimulated for a few days, after which it fell to the normal ratio.

In order to ascertain whether or not the lowering of the energy of respiration is due to the rapid and considerable loss of water, another part of the material was kept in a moist chamber instead of the laboratory room. It was found, however, that the production of carbon dioxid in this latter test differed little from that in the remaining tubers. This is claimed to show that a slight loss of water is sufficient to weaken the energy of respiration. It was not found

possible to establish any definite correlation between the amount of water lost and the intensity of respiration.

The effect of salt concentration on the germination of seeds, J. W. SHIVE (New Jersey Stas. Rpt. 1916, pp. 455–457).—Observations are recorded upon the amount of water absorbed by air-dry seeds of beans and corn and upon the germination of the seeds in sand cultures to which had been added solutions of MgSO4, KNO, Ca(NO3)2, KCl, KH,PO., and K,CO, varying in concentration from 0.5 to 8 atmospheres of possible osmotic pressure.

The average percentage of germination for the highest and lowest salt concentrations was practically the same and only slightly lower than that for the control cultures. The amount of water absorbed per gram of air-dry seed was considerably less for the cultures with the highest concentration than for those with the lowest concentration or the control cultures, resulting in retarded germination for the higher salt concentrations. Injury to the root tips occurred in concentrations as low as 2 atmospheres.

A study of physiological balance for buckwheat grown in three-salt solutions, J. W. SHIVE (New Jersey Stas. Bul. 319 (1917), pp. 4–63, figs. 13).—The results are given of an experimental study of the growth of young buckwheat plants in water cultures, comparisons being made with similar studies on wheat plants previously noted (E. S. R., 36, p. 328). The methods of investigation were the same for both kinds of plants, the object of the experiments being to determine the physiological balance of the salt proportions in the nutrient media and the total concentration of the media. Data are given relating to the dry yields of tops and roots, to transpirational water loss, and to water requirements of tops and roots.

The results of this investigation have been noted elsewhere (E. S. R., 39. p. 630). In general, it was found that the different criteria of plant measurements for buckwheat show a greater variety of more clearly defined relations between growth and the properties of the solution in which the plant grew than do the different criteria of plant measurements for wheat.

Effect of different oxygen pressures on the carbohydrate metabolism of the sweet potato, H. HASSELBRING (Jour. Agr. Research [U. S.], 14 (1918), No. 7, pp. 273-284).—In this contribution from the Bureau of Plant Industry, continuing studies on the carbohydrate transformation in the sweet potato (E. S. R., 34, p. 522), the author reports an investigation to determine the effect of oxygen pressures on the carbohydrate metabolism of the sweet potato root.

It was found that under gas pressures of 5 atmospheres or more, sweet potatoes were killed. In the killed tissues starch hydrolysis was greatly depressed or inhibited. Cane sugar was converted by hydrolysis into reducing sugars which accumulated in the root. Starch hydrolysis and cane sugar formation in the sweet potato were found to proceed in the absence of oxygen in the same manner as in air or in an atmosphere of oxygen, indicating that the presence of oxygen is not always a necessary condition for the formation of cane sugar in plant organs. The quantity of material consumed in a given period of time in anaerobic respiration by the sweet potato was greater than the quantity consumed in normal respiration at the same temperature. The actual carbon-dioxid output was also greater under anaerobic conditions. Cane sugar appeared not to be consumed in either process.

Transformations of (the) inulin of Jerusalem artichoke during the resting period, H. COLIN (Comp. Rend. Acad. Sci. [Paris], 166 (1918), No. 7, pp. 305– 307). The author finds that in resting tubers of Jerusalem artichoke inulin is changed partly into saccharose and partly into levulose, the absolute rotary power of which is less than that of inulin.