(E. S. R., 38, p. 86) well suited to this purpose. In this case the solid manure and litter should be kept in a sheltered and compacted heap with a tank to collect the drainings.

Nitrification of manure in the field, C. BARTHEL (Meddel. Centralanst. Försöksv. Jordbruksområdet, No. 150 (1917), pp. 13; K. Landtbr. Akad. Handl, och Tidskr., 56 (1917), No. 5, pp. 402-412; abs. in Chem. Abs., 12 (1918), No. 7, p. 736).-Investigations are reported which indicate that more or less ammonia nitrogen is produced in the course of five months in manure spread in the field, but that this does not account for all of the ammonia nitrogen fixed in the manure during this period. The nitrate nitrogen formed from the ammonia nitrogen was found to be practically constant and independent of the absolute amount of manure added to the soil. Nitric nitrogen developed fully as well in acid soils as in neutral soils. Previous observations of the author that the ammonia nitrogen changes into nitrate nitrogen less readily than organic nitrogen were confirmed, this being probably explained by the increase of hydrogen-ion concentration resulting from the transformation of ammonium sulphate.

Why not fertilize in the hill? C. E. THORNE (MO. Bul. Ohio Sta., 3 (1918), No. 6, pp. 182, 183).-The advantage of broadcasting fertilizers and manure over hill fertilizing, with particular reference to the effect upon the succeeding crops as demonstrated by results obtained with crops grown in rotation at Wooster and at Strongsville, is briefly discussed.

Absorption and nitrification of ammonium compounds in the presence of zeolites in soil. Estimation of ammonia in soil and on zeolithic substances, F. MÜNTER (Landw. Vers. Stat., 90 (1917), pp. 147-189; abs. in Jour. Chem. Soc. [London], 112 (1917), No. 662, I, pp. 722, 723).-Experiments are reported which show that sandy soils are capable of absorbing ammonia from ammonium sulphate to an appreciable extent and that over 10 per cent of the ammonia so absorbed can not be recovered by distillation with magnesia.

The addition of zeolites increased the amount of ammonia absorbed by a further 20 to 25 per cent of the total added. The ammonia held by the sandy soil was found to be more easily nitrified than that absorbed by zeolites. The ammonia retained by zeolites, when boiled with magnesia, was completely recovered by a further addition of potassium chlorid before distillation. That retained by soil was found to be more resistant to this treatment. Pure sand did not absorb ammonia and the addition of silicic acid and aluminum hydroxid was without effect.

"The hydroxids and carbonates of calcium, barium, strontium, and sodium, with or without the addition of neutral salts, either fail to expel all the absorbed ammonia or else lead to decomposition of the soil organic matter. The general conclusion is drawn that adsorption and absorption occur simultaneously in the soil without any definite relation existing between the two."

Trials on grassland with open-hearth basic slag and rock phosphates, G. S. ROBERTSON (Jour. Bd. Agr. [London], 24 (1918), No. 10, pp. 1077–1086).—The author presents a preliminary report on tests of the relative value of low and high citric-soluble phosphates on meadow hay grown on three types of soil in Essex. The experiments were planned primarily to determine the value of open-hearth basic slag, or fluorspar slag, recommended for use by Gilchrist and Louis (E. S. R., 37, p. 723), and they include a comparison of high-grade basic slag with a solubility of the phosphate in 2 per cent citric acid, of 92 per cent Gafsa rock phosphate with a solubility of 38.3 per cent, and two low-grade slags with solubilities of 93.4 and 82.2 per cent, respectively. The fluorspar slag employed had a solubility of 45 per cent. The results obtained in 1916 and in

1917 are tabulated, showing the yields of hay on each soil type and for each treatment, and are briefly discussed.

The average increases for all the tests over the untreated checks amounted to 36.8 per cent for the high-grade basic slag, 28.2 per cent for Gafsa rock phosphate, 42.6 per cent for fluorspar slag, and 31.3 and 37.4 per cent, respectively, for the two low-grade high-soluble slags. The use of flourspar slag is recommended for improving poor pasture and meadow land, and the normal high-soluble slags are recommended for cereal crops.

Reverted phosphate, C. C. JAMES (Jour. Indus. and Engin. Chem., 10 (1918), No. 1, pp. 33-35, figs. 3).—A study in continuation of previous work (E. S. R., 38. p. 122) of the rate and extent of reversion of acid phosphate, when mixed with varying amounts and combinations of lime and calcium carbonate in laboratory experiments and factory tests, showed that complete reversion was obtained in a comparatively short time, but more quickly with lime than with calcium carbonate.

The author states that he has found "in numerous cases that the reverted phosphate is just as valuable or even more valuable than the water-soluble when applied to cane upon upland soils. These soils are, as a rule, highly ferruginous clays. On soils which have not been cropped for several years the reverted phosphate gives excellent results."

The phosphate production and resources of the world, P. G. MORGAN (Jour. Agr. [New Zeal.], 16 (1918), No. 2, pp. 76–82).-This is a summarized discussion of available information obtained from various sources relative to the world's production and supply of phosphates.

Awards for the location of workable phosphatic deposits in Germany (Abs. in Internat. Inst. Agr. [Rome], Internat. Rev. Sci. and Pract. Agr., 9 (1918), No. 1, p. 42).—In order to increase the output of phosphates, of which there has been a shortage since the beginning of the war, "awards to the amount of 100,000 marks ($23,800) have been offered for the location of new phosphate deposits and for their study, either within the German Empire or in the occupied territories in the East."

The collection of kelp in the United States for potash production (Abs. in Internat. Inst. Agr. [Rome], Internat. Rev. Sci. and Pract. Agr., 9 (1918), No. 1, p. 43). Special attention is given in this article to the methods and machinery used in collecting the kelp.

Influence of gypsum upon the solubility of potash in soils, P. R. MCMILLER (Jour. Agr. Research [U. S.], 14 (1918), No. 1, pp. 61-66).-Experiments at the Minnesota Experiment Station are reported which showed that when various soils mixed with 1 per cent of gypsum were kept under moisture conditions similar to those prevailing in the field (approximate moisture equivalent) for three months, there were marked increases in the content of water soluble potash. It is suggested that "the results in previously reported experiments by various investigators in which the action of gypsum has not been found to cause such an increase may be due to the conditions of contact between the soil and gypsum that they have employed being unlike those that obtain in the field."

Analyses of county limestone deposits, J. W. AMES (Mo. Bul. Ohio Sta., 3 (1918), No. 7, pp. 222, 223).—This reports the results of analyses of 254 samples of limestone from different sections of Ohio, showing the percentage of calcium carbonate equivalent to the neutralizing power of the calcium and magnesium content of the sample. The results "indicate that there are numerous undeveloped supplies which could be utilized locally to good advantage pro91574-19 -3

viding the quantity is sufficient to warrant installing a pulverizing outfit in the community."

An agronomic study of several fertilizing or anticryptogamic compounds used in agriculture, B. DE WILKOSZEWSKI (Arch. Sci. Phys. et Nat. [Geneva), 4. ser., 44 (1917), pp. 165-189; abs. in Jour. Chem. Soc. [London], 112 (1917), No. 662, I, p. 723).—Examinations of percolates through columns of natural and artificial soils of different types treated with solutions of various salts showed that "iron in solution as ferric sulphate is more rapidly absorbed by the soil than in the ferrous state, any iron retained from ferrous sulphate being found in the ferric state in the soil. The salts are converted into their hydroxids, the ferrous hydroxid being subsequently oxidized and held in the soil in the ferric state. This hydrolysis is markedly favored by the presence of the soil particles. Similar results were obtained with manganese sulphate and copper sulphate, the salt in all cases undergoing hydrolysis and, where possible, oxidation, the base being retained in the soil and the acid ion passing on into the drainage water. "In the case of calcium cyanamid this material is converted into carbamid, ammonium carbonate, and subsequently calcium nitrite and nitrate, the reaction being much more rapid where a solution is used than where the solid is itself mixed into the soil. The author considers that microorganisms are not essential for these changes, as they occurred in a sterilized soil. The oxidation to nitrite and nitrate goes on most rapidly in soils of a porous nature, such as the infusorial earths."

Sulphuric acid and fertilizer industries (Chem. Trade Jour., 62 (1918), No. 1607, pp. 203–207; rev. in Jour. Bd. Agr. [London], 25 (1918), No. 2, pp. 193198). This is a report of a committee appointed by the Minister of Munitions of Great Britain "to consider and report on the position of the sulphuric acid and fertilizer trades as affected by the new acid plants which have been erected during the war by the Minister of Munitions for the Government."

The committee estimates that there has been a 60 per cent increase in production of sulphuric acid since the beginning of the war, one-half of this increase being derived from works owned or controlled by the Government and operated mainly for supplying munitions works. Of the prewar production about 30 per cent was consumed in the manufacture of superphosphates and an equal amount in the manufacture of sulphate of ammonia. The prewar production capacity was considerably larger than the actual output.

At the outbreak of the war the output of ammonia amounted to 400,000 tons per annum expressed as sulphate. "About 15 per cent of this production was not put on the market in the form of sulphate, but was converted into other ammonia products. The home consumption of sulphate of ammonia for agricultural purposes was only 60,000 tons per annum, and the remainder was mainly exported." During the war "the production of sulphate of ammonia has, however, suffered a temporary decline, owing to the diversion of large quantities of ammonia to the production of nitrate of ammonia. In view of the requirements of sulphuric acid for explosives manufacture, plants have been erected on a considerable scale for the conversion of crude ammonia into concentrated ammoniacal liquor. A substantial proportion of the requirements of ammonia for munitions purposes have thus been purchased in a form which requires no sulphuric acid for its manufacture. The total production of sulphate has thus been temporarily reduced from 350,000 tons to a little over 250,000 tons. At the same time, there has been a large increase in the home consumption for agricultural purposes, owing to the substitution of this fertilizer for nitrate of soda, the entire supply of which has been required for explosives manufacture. The export trade has nearly disappeared."

...

"For some years before the war the manufacture of superphosphate. . . was in a very unsettled condition owing to the rapidly increasing importation of foreign manufacture and the gradual decline in the export trade. The export of superphosphates had reached a maximum of 160,000 tons in 1911, but had afterwards declined to 63,000 tons in 1913. . . . As in the case of sulphuric acid, the available plant was capable, if continuously worked, of producing considerably more than the actual requirements of superphosphate. ... The production of superphosphate has been very materially reduced during the war owing to the lack of sulphuric acid. The production of superphosphate in 1916 fell to about 500,000 tons, as compared with about 800,000 tons in 1913. During the last few months, however, the paramount necessity of increasing the home-grown food supply has been realized, and steps have been taken to secure a large and immediate production of superphosphate."

The committee is of the opinion that "by far the most important prospect of utilizing the increased quantities of acid is in the manufacture of artificial fertilizers," and that "the large surplus of sulphuric acid plants which will become available at the end of the war provides an opportunity of an altogether exceptional nature for the development of a vigorous agricultural policy in relation to the efficient cultivation of the soil." It therefore recommends that the Government take every possible step through the exercise of its compulsory powers and by the use of educational methods of various kinds to extend the use of fertilizers.

Value of Philippine composts, F. B. SARAO (Philippine Agr. and Forester, 6 (1918), No. 5-6, pp. 128–134).-This reports the results of observations on the rate of decomposition and shrinkage, the percentage of moisture and total nitrogen, and the increase in total nitrogen in different materials composted in walled and unwalled and shaded and open piles. The materials studied included corn, cane, and sorghum trash; mixed herbaceous plants, including tomato and pea vines and amaranthus and other weeds; rice straw; cogon (Imperata sp.); bamboo leaves; and banana stems and leaves.

The cane trash compost showed the highest percentage of nitrogen, 0.9 per cent, that from corn trash and mixed herbaceous plants being next in order with 0.84 per cent each. Banana stems and leaves showed the highest shrinkage, and together with rice straw, composted most rapidly. Cogon showed the lowest shinkage. No relation between the rate of decomposition and the percentage of nitrogen content in the compost was observed.

Water hyacinth (Eichornia crassipes): Its value as a fertilizer, R. S. FINLow and K. MCLEAN (Agr. Research Inst. Pusa Bul. 71 (1917), pp. 16, pl. 1).— Analyses of the water hyacinth, said to occur as a noxious weed throughout the Dacca District of Bengal, are noted, and show the rotted or dried plant and ash to be quite rich in potash. The rotted material, containing about 65 per cent moisture, showed approximately 0.57 per cent nitrogen, 0.28 per cent phosphorus, and 2.57 per cent potash, while the dried plant contained from 1.5 to 2 per cent nitrogen and about 8 per cent potash. The ash showed from 25 to 35 per cent potash, mostly as chlorid, and in addition relatively large amounts of sodium, lime, and phosphoric acid.

Marked results were obtained from the use of both the rotted material and ash as a potash fertilizer for jute in rather extensive field tests on laterite soils of the old alluvium in Bengal.

The water hyacinth as a source of potash, F. W. F. DAY (Agr. Bul. Fed. Malay States, 6 (1918), No. 7–8, pp. 309–314).—In connection with work suggested by the article noted above, analyses were made of water hyacinths collected from different parts of the Federated Malay States, and similar results were obtained.

Whale fertilizer (Agr. Gaz. Canada, 5 (1918), No. 4, p. 370).-It is reported that the Department of Agriculture of Canada “has purchased for distribution in the Province [of British Columbia] 50 tons of whale fertilizer. It is manufactured from whale meat and blood, the oil having been extracted. Analysis shows it to contain 12.4 per cent of nitrogen. It is being sold to farmers and farmers' organizations at approximately $72 per ton, which includes transportation."

Sources of fertilizing materials for Illinois farms, C. G. HOPKINS and F. C. BAUER (Illinois Sta. Circ. 223 (1918), pp. 8, fig. 1).-Information is presented relative to sources of supply readily available to Illinois farmers of agricultural limestone, limestone crushing machinery, limestone and phosphate spreaders, raw rock phosphate, bone meal, and potassium salts.

AGRICULTURAL BOTANY.

A promising chemical photometer for plant physiological research, C. S. RIDGWAY (U. S. Mo. Weather Rev., 46 (1918), No. 3, pp. 117-119).-Attention is called to a chemical photometer which, so far as tested, seems adapted to use in investigations of the light relations of plants. The principle on which the photometer is based is the reaction of light to a mixture of oxalic acid and uranium salts. Comparisons were made with a pyrheliometer, the length of exposure of the solutions ranging from 8 to 24 hours, and very close agreements were shown. Other experiments conducted for the purpose of measuring the intensity of sunlight on clear days produced curves very similar to records obtained with the pyrheliometer.

The author claims that some of the probable advantages of the method are the ease and low cost with which it may be operated, the avoidance of compli cated, costly, and frequently unreliable mechanisms, and the reduction of error due to the personal factor in observation, so prominent in the photographic paper method.

A comparison of salt requirements for young and for mature buckwheat plants in water cultures and sand cultures, J. W. SHIVE and W. H. MARTIN (Amer. Jour. Bot., 5 (1918), No. 4, pp. 186–191).—In a preliminary presentation of the main results of an attempt to determine the best proportions of the 3-salt nutrient solution previously employed by Shive (E. S. R., 34, p. 333) and here used according to methods described by him (E. S. R., 36, p. 328), the authors state that the salt proportions giving the best physiological balance for buckwheat during the early and the late period of growth and maturation as here considered differ markedly and in the same manner with water cultures and with sand cultures. In three of the four series a definite correlation appeared between the growths of tops and that of roots. The 3-salt mixture had a total osmotic concentration of 1.75 atmospheres and with proper salt proportions produced markedly higher yields than did either Knop's or Tottingham's solution with the same concentration for the two growth periods here used.

The origin of inulin in plants, H. COLIN (Compt. Rend. Acad. Sci. [Paris]. 166 (1918), No. 5, pp. 224-227).-The tabulated results of studies on Jerusalem artichoke and chicory show that those portions of the plants which contained starch contained no inulin. In other portions the ratio of inulin to the total sugars present increased from the root tips to the crown and was found to be increasingly, though slightly, greater in the smaller tubercles, stolons, and larger tubercles.

Respiration and catalase activity in sweet corn, C. O. APPLEMAN (Amer. Jour. Bot., 5 (1918), No. 4, pp. 207–209, fig. 1).-Having shown (E. S. R., 36, p. 329) a relation between the respiratory activity of potato tubers and catalase activity