Manuring Hops. By C. KRAUS (Bied. Centr., 1887, 785-786).— In general the manure should contain three plant-foods, phosphoric acid, potash, and nitrogen, and contain some organic substance, which by its decay will slowly render those foods available. Guano made from fæces in moderate dressings is preferable to the potashammonia-superphosphate formerly recommended; it acts better even than mixtures of sodium nitrate and superphosphate containing the same amounts of plant-food. Rape-cake meal would appear to be suitable on the above grounds, and in France it has been found to give good results. These manures are like farmyard manure both in chemical nature and physical effects, and, as with farmyard manure, care must be taken to avoid over manuring. Although nitrogen is of the greatest importance to the hop, as it is to other plants, yet it is possible to give too much of it, and so cause injury. If nitrogenous manures are employed alone on the poorer soils, the yield will not be a full one, and even on the better soils the crops will in time fall off. Potash and phosphates should only be employed without nitrogen when a trial has proved that there is enough nitrogen stored up in the soil, and that nitrogenous manuring will not increase the yield without injuring the quality.

In good situations, artificial manure in addition to farmyard manure is the best means of realising the profit which the locality affords.

H. H. R.

Manuring Sugar Beets with Basic Slag. By E. V. PROSKOWITZ (Bied. Centr., 1887, 739-742).-The trial was made in Kwassitz on an alluvial soil in low marshy country. The plots were 100 square metres (0.025 acre) in area. The manures employed were a basic slag and a superphosphate. The slag contained 20.5 per cent. of phosphoric anhydride, only 0.04 per cent. being soluble in citrate solution. Its state of division was one of medium fineness. The superphosphate contained a total of 17.3 per cent. of phosphoric anhydride, 12:44 per cent. being soluble in water.

The unmanured plots all suffered from root decay. The best matured roots (as indicated by their having the smallest proportion of leaves to roots) were on the plots manured with superphosphate. The author concludes that in that particular neighbourhood, on heavy clay land, the basic slag was less effectual than the customary quantity of superphosphate, and that the time of applying it had no decided influence.

H. H. R.

Comparison of the Different Properties and Character of Manure made with Straw and with Turf Litter. By M. FLEISCHER (Bied. Centr., 1887, 808-814). As regards the value of straw or peat alone as manure, it appears that straw contains most potash, lime, and phosphoric acid, whilst peat moss litter contains most nitrogen, and when mixed with manure the peat manure contains more easily soluble nitrogen than the straw manure; the retention of soluble nitrogen (ammoniacal compounds) by peat therefore renders it somewhat more valuable than straw. Field experiments show that peat makes the better manure, especially on light land,

because of its retentive capacity for soluble nitrogen, consequently the after effects are greater than when straw is employed. lands, however, the question is not yet decided.

On heavy E. W. P.

Behaviour of Various Plants towards Nitrogenous Manures. By E. WOLFF and C. KREUZHAGE (Bied. Centr., 1887, 793-808).— The object in view was not to estimate the capability of plants to absorb nitrogen from the air either directly or indirectly, but rather to collect facts to prove that various plants are differently influenced by nitrogenous manures. To this end plants were sown in artificial soils, the base being sand, in some cases calcined, in others in the ordinary state, and the experiments extended over some years. Some plants received no added nitrogen, whilst others received increasing quantities. Full details of the weight of the crops harvested, the manures, &c., are given. The yield of straw crops (oats, &c.) is greatly increased by the addition of Chili saltpetre, but Leguminosa, beans, lupines, clover, &c., are not increased in yield even when the amount of added nitrogen is trebled. Beans, &c., remove from the soil more nitrogen than is contained in the original seed and the manure, whilst the opposite is the case with oats, &c. E. W. P.

Analytical Chemistry.

Gas Receiver for Absorption Analyses. By F. A. WILBER (Amer. Chem. J., 9, 418-420).-A peculiar form of eudiometer intended for the analysis of the gases obtained from potable waters.

Use of Asbestos for Assisting the Subsidence of Suspended Matter. By W. FRESENIUS (Zeit. anal. Chem., 27, 32-33).—In cases where, owing to the presence of very finely divided suspended matter, as in experiments on artificial digestion, it is difficult to get clear filtration, the subsidence of the solid particles may be greatly assisted by vigorously shaking with fibrous asbestos. M. J. S.

Determination of Sulphur, Chlorine, Bromine and Iodine in Organic Compounds. By P. CLASON (Ber., 20, 3065-3066).— This method consists in burning the substances in air charged with nitric acid. The nitric acid is contained in rolls of platinum gauze 5 cm. long and 1 cm. in diameter, filled with very small glass beads; these rolls absorb the acid readily, and it does not run out when the rolls are placed horizontally. The combustion tube is connected at one end to the air supply, then come two nitric acid rolls, a roll without nitric acid, boat containing the substance, two rolls without nitric acid placed a small distance apart, after an interval two more nitric acid rolls, and lastly a roll without acid; the end of the tube is drawn out, bent downwards, and dips into a flask containing water, or, in the

case of chlorine and bromine combustions, a solution of silver nitrate. The combustion is conducted in the usual manner, the empty rolls in the front part of the tube being first heated to redness, and the substance and acid rolls then so heated that a steady stream of nitrous fumes issues from the exit tube. A. J. G.

Comparative Value of some Proposed Tests for Nitric Acid. By P. WALDEN (Chem. Centr., 1887, 1180-1181, from J. Russ. Chem. Soc., 1887, 274-295).-Brucine gives a feeble coloration with solutions of potassium nitrate, 1: 500000, and of potassium nitrite, 1:1100000. Diphenylamine is equally delicate. The author does not recommend phenol or toluidine. For nitrous acid, diamidobenzoic acid, metaphenylenediamine, naphthylamine and amidobenzeneorthosulphonic acid are recommended, their delicacy being 1:5000000. The colour reaction with naphthol is not characteristic for nitric and nitrous acids nor for chlorine; it is much less delicate than the brucine and diphenylamine tests. Nitric and nitrous acids in presence of other oxidising agents can be detected in the following way:- -Concentrated sulphuric acid and the solution in question are added to an alcoholic solution of B-naphthol. The solution is coloured red, yellowish, or cinnamon, and shows fluorescence, which is not caused by the other oxidising agents. The delicacy is one in 300,000. These reagents can only be used as group reagents, the colours being produced by any energetic oxidising agent. If nitric and nitrous acids are both present, the former can be detected by the compounds mentioned with toluidine. The nitrous acid is then destroyed by an excess of carbamide and sulphuric acid, and the nitric acid which has remained unchanged can be detected by means of brucine or diphenylamine. In water analysis, where there are no other oxidising agents present, brucine, diphenylamine, and metaphenylenediamine are to be preferred to zinc iodide and starch-paste. The author finally recommends a solution of diphenylamine in concentrated sulphuric acid as a reagent for chromic acid, which produces quickly a fugitive blue colour even with a dilution of one part potassium dichromate in 700,000. J. W. L.

Presence of Sodium Phosphate in Glacial Phosphoric Acid. By A. BETTENDORFF (Zeit. anal. Chem., 27, 24-26).-The phosphoric acid in sticks found in commerce frequently contains sodium phosphate, which communicates hardness to the otherwise soft glassy acid. It can be detected by dissolving the solid in fuming hydrochloric acid, when the sodium remains undissolved as chloride. A quantity of sodium pyrophosphate (ignited to destroy organic matter) dissolved in hydrochloric acid of 1·19 sp. gr., left 98.5 per cent. of its sodium as chloride. One part of sodium chloride requires 1348 parts of this acid at 12° for its solution. This furnishes a direct method of preparing phosphoric acid from sodium phosphate.

M. J. S.

Estimation of Phosphoric Acid in Basic Slag. By G. KENNEPOHL (Chem. Zeit, 11, 1089-1091).—The author confirms the opinion expressed by Klein (Abstr., 1886, 835), that there is little or no iron phosphide in basic slag. The phosphoric acid in basic slag

may be accurately determined in the following manner: 10 grams of the finely powdered slag (moistened with alcohol to prevent adherence) placed in a 500 c.c. flask, is heated with 40 c.c. of hydrochloric acid, sp. gr. 1.12, and 40 c.c. of water, for at least a half an hour on a water-bath; if much ferrous salt is present, it is well to add a little nitric acid or bromine before heating. An aliquot part of the filtered solution is mixed with ammonium nitrate and molybdate solution, without previous removal of the silica. The solution, after heating at about 80° for 15 minutes, is filtered, and the precipitate washed with water containing 3 per cent. of nitric acid (to remove adhering iron salts), redissolved in 2.5 per cent. ammonia, and then precipitated with magnesia mixture. The presence of silica does not interfere, owing to the ready solubility of ammonium silicomolybdate in the washing water. D. A. L.

Estimation of Arsenic in Pyrites. By H. FRESENIUS (Zeit. anal. Chem., 27, 34-35).—To ascertain whether by fusion the whole of the arsenic could be obtained in alkaline solution, about 10 grams of pyrites was intimately mixed with two parts of sodium carbonate and one part of potassium nitrate. The mixture was fused and thoroughly exhausted by boiling with sodium carbonate solution. The filtrate was neutralised with hydrochloric acid, mixed with ferric chloride, and precipitated by calcium carbonate. The precipitate was distilled with ferrous chloride and hydrochloric acid as long as arsenic passed over. The undissolved residue from the fusion was also dissolved in hydrochloric acid and distilled with ferrous chloride. In the latter distillate, about 9 per cent. of the whole quantity of arsenic was found. The method therefore presents no advantages over direct distillation in a current of chlorine, or distillation with ferrous chloride, after dissolving in hydrochloric acid with addition of potassium chlorate. M. J. S.

Estimation of Oxygen, Carbonic Anhydride and Carbonic Oxide. By J. SINIBALDI (Bull. Soc. Chim., 48, 244-246).-An apparatus somewhat resembling Elliott's gas analysis apparatus in principle, but not intelligible without the diagram. C. H. B.

Apparatus for Direct Determination of Carbonic Anhydride. By O. OSTERSETZER (Zeit. anal. Chem., 27, 27-30).—A conical flask of 70 c.c. capacity is closed with a caoutchouc stopper bored with two holes. Through one passes a tube bent at a right angle. This is the inlet for washed air. Below the stopper the diameter of this tube is reduced so that when raised it is loose in the hole. Near its lower end it has a glass hook on which is hung the glass bucket containing the carbonate. At the end it is drawn out to a point which is turned upwards. The other hole carries a Welter's safety bulb tube joined to a Geissler's drying tube. Both of these contain sulphuric acid. Into the upper end of the Geissler's tube is ground a small cylinder for holding pumice saturated with copper sulphate, and the potash bulbs. for absorbing the carbonic anhydride are directly connected to the

upper end of this. To use the apparatus, the inlet tube is raised, and the bucket containing the substance is hung on its hook. A small excess of highly dilute acid is placed in the flask, and all the connections are made. The tube carrying the bucket is then pushed down into the acid, its wider portion immediately making it fit tight in the stopper. Purified air is gently aspirated through during the decomposition, and finally the flask is shaken and gently warmed.

M. J. S.

Analysis of German Silver. By F. OETTEL (Zeit. anal. Chem., 27, 15-18). This alloy consists of copper, nickel, and zinc, but may also contain tin, lead, iron, cobalt, and manganese. The copper can with certainty be separated from zinc by one precipitation by hydrogen sulphide from a sulphuric acid solution, although not from a nitric acid solution. The solution of 0.5 gram of the alloy in nitric acid (which is consequently free from tin), is evaporated with sulphuric acid, which removes lead. It is then diluted to 100 c.c., acidified with 2 c.c. of strong hydrochloric acid, and precipitated by hydrogen sulphide. It is heated to boiling and re-cooled before filtering, and the precipitate is washed with dilute aqueous hydrogen sulphide, adding a little hydrochloric acid at first.

The filtrate is evaporated to remove hydrochloric acid, diluted, neutralised with potash, mixed with a few drops of sodium acetate, and saturated in the cold with hydrogen sulphide; zinc sulphide separates in a pulverulent form, easily filtered and washed. The hydrogen sulphide is removed from the filtrate by boiling, the iron is oxidised by bromine (not by nitric acid), and precipitated by ammonia. The concentrated filtrate is made strongly alkaline with ammonia and electrolysed. Nickel and cobalt are deposited together on the platinum cylinder, whilst the manganese separates as hydrated peroxide. Precipitation of the nickel by an alkali is only to be trusted when performed in platinum vessels. The copper and lead can also be determined electrolytically. By electrolysing a nitric acid solution of the nitrates with four small Daniell cells, the copper from 0.5 gram of the alloy can be completely deposited in three hours, the lead at the same time separating as peroxide which can be weighed. If a sulphuric acid solution is electrolysed, the copper separates as a red mud, which can be filtered off after stopping the current, leaving the other metals for determination as above.

M. J. S.

Separation of Aluminium and Beryllium. By A. ZIMMERMANN (Zeit. anal. Chem., 27, 61–63).—Of all the processes hitherto proposed that based on the precipitation of beryllia, when its solution in potash is boiled, seems to be the best. A very pure potash (purified by alcohol and heated till free from organic matter) is requisite. The solution of 0.3 gram of substance must not exceed 300 c.c., or alumina will be precipitated with the beryllia. After 15 to 20 minutes' boiling in a platinum basin much hot water is added, and the beryllia is filtered off and washed. It is free from potassium.

When the two earths are present in about equal quantities, but not otherwise, they may be completely separated by neutralising with