solution gives no precipitate, but if hot narceïne chromate and free narceïne come down. Thebaïne gives thebaïne chromate. Codeïne also gives the corresponding chromate, whilst morphine gives chromate and free morphine.

With potassium dichromate, narcotine, papaverine and thebaïne give the corresponding dichromates, narceïne gives the dichromate and free alkaloid. Codeïne in very dilute solution gives the dichromate; stronger solutions afford precipitates which have not yet been examined. Morphine gives a dirty brown precipitate of variable composition.

With potassium ferrocyanide, narcotine hydrochloride gives free alkaloid or a mixture of variable composition; the papaverine salt gives (C2H2NO.),H,Cfy; the narceïne salt gives free alkaloid, the hydroferrocyanic acid becomes free; the thebaïne salt gives the compound (C19H2NO3), H,Cfy; the codeïne salt solution (1: 70) is not precipitated; the morphine salt solution (1 : 60) is not precipitated. With potassium ferricyanide narceïne gives the salt

(C22H23NO7) 6, H.Cfdy;

papaverine and thebaïne give similar precipitates, narceïne gives free alkaloid, hydrogen ferricyanide also becomes free; codeïne in solution (170) gives no precipitate; morphine solution (1: 60) becomes dark coloured and a brown deposit forms after long standing.

J. T. Quinine Alkaloïds. By O. HESSE (Annalen, 243, 131–150).— Quinine tartrate crystallises with 2 mols. H,O; it parts with one. mol. H2O at 120°, and the second at 140°. A mixture of quinine and cinchonidine tartrates loses water more easily than quinine tartrate, but if the mixture contains more than 33 per cent. of quinine tartrate, it cannot be thoroughly dried by exposure to a temperature of 120-130°. If ammonia is added to a solution of quinine disulphate containing not more than 10 per cent. of cinchonidine disulphate, ether extracts from the mixture the compound CH2N2O2 + 2C19H22N2O. This substance crystallises in rhombohedra, and is decomposed by boiling ether. On recrystallisation from hot dilute alcohol, crystals of the composition CH2N2O2 + 7C1HN2O are obtained. The compound CH2N2O2 + 2C19H2N2O forms a normal sulphate crystallising with 18 mols. H2O, a normal tartrate containing 6 mols. H2O, and a normal chromate with 18 mols. H2O.

The estimation of quinine as chromate as proposed by de Vrij (Abstr., 1887, 404) is open to several objections (loc. cit.).

The author confirms the existence of the compound of quinine and conchinine described by Wood and Barret (Chem. News, 45, 6) and he succeeded in preparing a similar compound of quinine and hydroconchinine, CÁH2N2O2,CÓHÁN2O2 + 21⁄2H2O.

With cinchonidine and homocinchonidine, piperonylic acid forms salts crystallising in needle-shaped crystals soluble in chloroform. The hydrocinchonidine salt is soluble in water and in chloroform. Quinine sulphate is converted into isoquinine by solution in strong sulphuric acid. The new base forms a normal sulphate which crystallises in small needles. It does not yield a precipitate with sodium

tartrate. Isoconchinine is deposited from ether in needles. The sulphate, (C20H2N2O2)2, H2SO, +8H2O, is crystalline, and the platinochloride, CHN2O,H2PtCl + 3H2O, is amorphous. Isocinchonidine crystallises in colourless plates, freely soluble in ether and chloroform. It melts at 235°. Isocinchonine is freely soluble in ether. On evaporation, the ethereal solution leaves an amorphous residue which soon becomes crystalline.

Hydroconchinine yields a crystalline sulphonic acid,

C20H25N2O2 SO2H + 5H2O.

W. C. W.

Optical Isomerides of Cinchonine. By E. JUNGFLEISCH and E. LEGER (Compt. rend., 105, 1255-1258).-Pure cinchonine dissolved in four times its weight of a mixture of equal parts of water and sulphuric acid of sp. gr. 184, yields a colourless solution which boils at 120°. After boiling for 48 hours, the liquid is amber-coloured, but does not become turbid on cooling. When diluted and made alkaline with sodium hydroxide, it yields an abundant curdy precipitate which soon changes to a porous mass, and gradually hardens. This product contains neither cinchonine nor cinchonicine, but consists of six bases, four of these are isomerides of cinchonine, which form readily erystallisable salts.

Cinchonibine is insoluble in ether but crystallises from boiling alcohol in prismatic needles. It yields a succinate which forms bulky crystals slightly soluble in cold water. It is dextrogyrate, [x]D = +1758°, in an alcoholic solution of 0.75 per cent.

Cinchonifine is insoluble in ether, but crystallises from boiling alcohol in highly refractive needles. It is dextrogyrate, [a]D =+195·0°, in an alcoholic solution of 0.75 per cent. The succinate crystallises in needles, and is very soluble.

Cinchonigine is soluble in ether, from which it crystallises in prisms, and is lævogyrate, [x]D = -601°, in an alcoholic solution of 1 per cent. It yields a distinctly crystalline hydrochloride slightly soluble

in water.

Cinchoniline is soluble in ether, and forms very bulky crystals. It is dextrogyrate, [x]D = +53-2°, in an alcoholic solution of 1 per cent. The hydrochloride forms large crystals which are very soluble; the dihydriodide is insoluble. These four compounds increase the number of isomerides of the composition C19HN2O to seven.

The other two bases are isomeric one with another, but belong to another group. They are products of oxidation produced with intermediate formation of a sulphonic derivative which is decomposed by water.

a-Oxycinchonine, CH2N2O2, forms prismatic needles insoluble in ether but soluble in dilute alcohol. It is dextrogyrate, [a]» : = +182:56°, in an alcoholic solution of 1 per cent. Its salts with the hydracids are only slightly soluble.

B-Oxycinchonine, CH2N2O2, is insoluble in ether, but dissolves in dilute alcohol, and crystallises in needles arranged in spherical groups. It is dextrogyrate, [a] = = + 187·14°, in an alcoholic solution of 1 per cent. Its salts with hydracids are very soluble.

C. H. B.

Cocaïne.

By A. EINHORN (Ber., 21, 47–51).—The ethereal salts of benzoylecgonine can be obtained by passing hydrogen chloride into its alcoholic solution; the ethyl, propyl, and isobutyl salts were prepared in this way; they have already been described by Merck (Abstr., 1886, 163).

Succinic acid is formed when anhydroecgonine or ecgonine is oxidised with potassium permanganate; 10 grams of ecgonine hydrochloride yield about 2.2 grams of succinic acid. Ecgonine hydrochloride also gives succinic acid when it is boiled for some time with nitric acid; from 2 grams of the salt, about 1 gram of succinic acid is obtained..

The atomic complex, C-CH, CHC, which is contained in succinic. acid, must originate from the reduced pyridine-ring of the cocaïnederivative, and the formation of succinic acid shows that the sidechain is either in the a- or B-position.

Nitrogenous compounds are also formed in the oxidation of ecgonine and anhydroecgonine. F. S. K.

Physiological Chemistry.

Behaviour of Congo-red with Human Urine and with Acid Salts. By E. BRÜCKE (Monatsh. Chem., 8, 632-637, compare Abstr., 1887, 986).-Human urine and a solution of ammonium acetate containing free acetic acid give similar tints with Congo-red. The addition of magnesium sulphate, however, in no way affects the colour of the former, whilst it causes the latter to darken rapidly with the formation of a brownish-black precipitate. The acid tartrates of ammonium and potassium give with Congo-red a beautiful violet colour. The author sees no reason to change the conclusion he draws from previous experiments with Congo-red, that human urine contains no free acid. G. T. M.

Chemistry of Vegetable Physiology and Agriculture.

Colour of Leaves in Relation to the Assimilation of Carbon. By T. W. ENGELMANN (Ann. Agronom., 13, 477-480; from Bot. Zeit., 1887, 25-29).-The yellow leaves of an elder bush were studied side by side with the green leaves of the same plant by means of Engelmann's microspectral photometer, and by their behaviour towards aerobic bacteria.

The absorption-spectrum of the living yellow cells shows that the bands II and III in the orange and the yellow-green which belong to the green colouring constituent (cyanophyll or pure chlorophyll), and

which are absent from the spectrum of xanthophyll, are scarcely indicated.

In the spectrum of the green living cells, on the other hand, these bands are easily identified, although Reinke, working with Glan's photometer, did not succeed in finding them. It would thus appear that the yellow cells contain little chlorophyll proper, or chlorophyllane, and it would be expected that they should lack the power of assimilation. By immersing equal areas cut out of the yellow and green leaves in a liquid charged with aërobic bacteria, and exposing the liquid to the light, it is easily seen that the yellow cells disengage far less oxygen in a given time than the green cells, and hence it is probable that if they contained pure xanthophyll only, the assimilating power would be nil.

With reference to the plants in which the light reaches the granules of true green chlorophyll through layers of cells coloured red or purple (copper-beech, red cabbage, &c.), the author observes that they do not differ from what is observed in green plants either in the disposition of the chlorophyll granules or in their size, or the nature or intensity of their colour. Moreover, the red varieties of a plant, for example, Coleus, are quite as large and vigorous as the green specimens. It follows that the red colouring matter of these plants can only absorb those rays which have little influence on assimilation.

The colouring matter is always a red-purple, which has most effect in absorbing the green rays, whilst red rays pass freely, and blue and violet very well. The curve of absorption rises about the middle of the spectrum, and descends again at the other end. When the solution is very concentrated a large absorption-band is seen between the wave-lengths λ = 0·59μ and λ = 0.50μ. Speaking generally, the absorption of light is complementary to that caused by solutions of chlorophyll. If, as was formerly believed, the maximum of assimilation corresponded with the yellow rays, that process would be much impeded in the red plants, for the yellow rays are enfeebled to the extent of one-third in passing through the red solution.

J. M. H. M.

Supply of Food Constituents at Different Periods of Plant Growth. By G. LIEBSCHER (Bied. Centr., 1887, 658-660).—As a basis for the science of manuring, the author advances a new theory. The view sometimes held, that one species of plant has a greater power than another of taking up some particular food constituent cannot be reconciled with the laws of osmosis; but the difficulties met with can be explained in another way. Each day the root should supply a certain amount of food to the plant; this amount varies more or less at different stages of growth, and further, these variations differ in the case of different plants; thus one species requires a fairly uniform daily supply throughout its period of growth, whilst another requires much more at one stage than at another. From the composition of various plants at different stages of growth, the author has constructed a number of curves showing how these supplies vary. Such information affords an important clue to the proper manuring of a particular species; thus for a plant requiring a uniform daily supply, a slowly decomposing and lasting manure is appropriate;

whilst an easily soluble one should be given to a plant whose demand is large during a short period. H. H. R.

Wheat Experiments in 1887. By A. LADUREAU and MOUSSEAUX (Ann. Agronom., 13, 538-551).-The experiments were carried out on the poor lands of the Brie district, and had for their object to demonstrate the utility of artificial manures, and to ascertain the most productive and economical manuring for the district. The soil, limed in 1885, contained only 0.084 per cent. N, 0.085 per cent. P2O5, 0.325 per cent. K2O, and 0.280 per cent. CaO.

One variety of wheat (Golden Drop) was sown on all the plots, on the same day, October 11th, 1886, at the uniform rate of 2 hectolitres per hectare; each plot measured 3 ares. Both straw and grain were weighed on each plot, the value calculated out at the price actually realised, and compared with the expense of the various manures used. The yield varied from 950 kilos. per hectare of grain, and 1550 kilos. straw on the unmanured plot, to 3200 kilos. grain and 5650 kilos. straw on the best plot, which was manured with 50 cubic metres farmyard manure, and 300 kilos. of 15 per cent. superphosphate per hectare in the autumn, and top dressed with 250 kilos. sodium nitrate in the spring. The increase obtained on this plot over the unmanured plot exceeded the cost of the manures applied by 319-75 francs per hectare. A still more favourable result (although from a smaller crop) was obtained on the plot dressed with 100-5 kilos. P2O, in superphosphate and 48.5 kilos. of ammoniacal nitrogen per hectare in the autumn, 29.75 kilos. nitrogen as sodium nitrate per hectare in the spring; on this plot, the increase obtained by the manure exceeded the cost of the latter by 389-4 francs per hectare. The results obained on all the plots justify the following conclusions:

1. Superphosphate applied at the rate of 50 kilos. per hectare produces an increase of crop on these soils.

2. Ammonium sulphate applied in spring gives results greatly superior to those given by the same money value of sodium nitrate.

3. Basic cinder substituted for some of the superphosphate did not give good results. The authors are now trying basic cinder alone, and expect to get better results with it. That employed in the present series of experiments was very coarsely ground.

4. Farmyard manure alone did not even repay its cost, a result probably due to the exceptional drought of the season. The authors recommend the wheat growers of this distrtct to sell their farmyard manure to the vine growers, and with a portion of the proceeds to buy artificial manures. J. M. H. M.

Experimental Culture of Sugar-beet at Grignon in 1887. By P. P. DEHÉRAIN (Ann. Agronom., 13, 529–538).-The experiments were to decide two points, namely, the quality of the seed obtained at Grignon from previous crops of Vilmorin's sugar-beet, and the effect of farmyard manure as compared with mineral manures on the yield of sugar. The plots sown with the Grignon seed were therefore compared with parallel plots sown with seed obtained direct from Vilmorin; the manures tried were farmyard manure, sodium nitrate, and