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The titre of beef fat is about 416 to 44; iodine absorption, 43·8 to 40; that of cotton-seed oil, 33.3, iodine absorption, 108. The one adulterant will therefore to some extent mask the other; they are, however, respectively revealed by Bechi's and Belden's tests. The high specific gravity of cotton-seed oil affords the only means of estimating the amount of it present. (See also Abstr., 1889, 319, 659.) M. J. S.

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Action of Acids on Benzoic Sulphinide and Analysis of "Saccharin." By I. REMSEN and W. M. BURTON (Amer. Chem. J., 11, 403—408).—When benzoic sulphinide, CH<S>NH [= 1 : 2], is boiled with dilute acids, hydrogen ammonium orthosulphobenzoate, COOH CH2SO2NH, [= 1: 2] is formed, together with a little orthosulphaminebenzoic acid, COOH CH, SO2NH2. The best strength of acid is that obtained by diluting strong hydrochloric acid of sp. gr. 1.17 with 8 to 10 times its volume of water.

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Commercial saccharin is found to be a mixture of parasulphaminebenzoic acid, benzoic sulphinide, and hydrogen potassium orthosulphobenzoate, the amount of sulphinide present being somewhat less than 50 per cent.

To analyse it, 2 grams are boiled for one hour with 100 c.c. of dilute hydrochloric acid (1-8) in a flask of 250 c.c. capacity, provided with a reflux condenser. The clear solution is then evaporated to about 15 c.c., when the parasulphaminebenzoic acid separates out; it is dried at 80° and weighed. The filtrate, containing hydrogen ammonium orthosulphobenzoate (from the decomposition of the sulphinide) and the hydrogen potassium salt of the same acid, is evaporated; the residue is weighed, and the amount of potassium in it is estimated by heating a portion with sulphuric acid, and weighing the potassium sulphate formed. Two samples of saccharin were analysed, each five times; the mean percentage composition of each is given below.

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Benzoic sulphinide. 42.86 48.33

COOH CH, SOK.

7.12

7.99

C. F. B.

Estimation of Morphine in Opium. By F. A. FLÜCKIGER (Arch. Pharm. [3], 27, 721-732, 769-772).—The author discusses various points which arise in the estimation of morphine, and arrives at the following fairly good, although not quite perfect, method. 8 grams of opium powder is placed in a folded filter of 12 cm. diameter with a little tapping, and is dried at 100°. After half an hour 10 c.c. of ether mixed with 10 c.c. of chloroform is poured over it, the covered funnel being frequently struck, and finally 10 c.c. more of chloroform is poured on. After all possible liquid has run through, the filter with its contents is opened out and dried at a gentle heat. Next the powder is vigorously and repeatedly shaken in a flask with 80 c.c. of water and filtered after two hours. 42.5 grams of the filtrate is well and often shaken in a weighed flask with 7-5 c.c.

of alcohol (0.83 sp. gr.), 15 c.c. of ether, and 1 c.c. of ammonia (0.96). After six hours, the contents of the flask are poured on to a doublefolded filter of 10 cm. diameter, and the morphine is washed on to the filter with about 10 c.c. of water. This is dried, returned to the dried flask, and dried at 100° until its weight becomes constant. This process with a particular sample gave 12.90, 13·12, 13:35 per cent. of morphine, which was not pure white, but which dissolved completely in lime-water with very little colour. As an appendix the author criticises in some detail an article by E. R. Squibb in the "Ephemeris for July, on morphine estimation, and, although he sees many defects in the process given, he remarks that the comprehensive paper deserves the fullest consideration, J. T.

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Analysis of Pepper and the occurrence of Piperidine in the By W. JOHNSTONE (Analyst, 14, 41-49).-Moisture and ash. -A weighed portion is dried at 100° and then incinerated in a muffle. The ash is treated successively with water and hydrochloric acid, and the amount of insoluble matter noted.

Oil.-20 grams is distilled with water; the distillate is shaken with ether, the ethereal solution is evaporated at a very low temperature, and the residue is dried over sulphuric acid.

Piperidine.-20 grams is distilled as for the oil determination, and the distillate is titrated with N/10 sulphuric acid (compare Abstr., 1889, 298). That the piperidine is not derived from the hydrolysis of piperine is shown by the fact that pure piperine yields no piperidine when distilled with water, also that in distilling pepper with water, piperidine soon ceases to come over, although the amount obtained is very small in comparison with the piperine present.

Piperine.-10 grams is digested at 100° in a closed bottle with 3 grams of potash dissolved in 25 c.c. of water and 25 c.c. of alcohol. The bottle (4 oz.) should have the neck ground flat and be closed by a plate of caoutchouc pressed tightly upon it by a screw-frame. After 4-6 hours' digestion, the bottle is cooled, the contents are washed into a large flask and distilled as long as the distillate is alkaline. The theoretical yield of piperidine is obtained.

Crude Fibre. A small quantity is boiled for half an hour in a flask with inverted condenser with 200 c.c. of dilute sulphuric acid (12.5 grams per litre). The residue is twice boiled with water, then with 200 c.c. of potash (12.5 grams per litre), and again twice with water. It is collected on a tared filter, dried and weighed, and any ash it contains deducted.

Nitrogen.-Determined by soda-lime, as usual.

Alcoholic Extract.-10 grams is extracted with 95 per cent. alcohol in a Soxhlet's apparatus for 24 hours. The alcohol is distilled off and the extractive matters dried at 100°.

Starch. The exhausted residue from the preceding is, without drying, washed into a flask with 200 c.c. of water and 20 c.c. of hydrochloric acid (1·121) and heated in boiling water for three hours. After cooling, the liquid is filtered, neutralised with soda, made up to 500 c.c., and titrated with Fehling's solution.

In 13 genuine samples from various localities, the moisture ranged

from 12 to 15 per cent., ash 1.07 to 4:46 (long pepper 7 57), oil 0·53
to 1.87, piperidine 0.21 to 0.77, piperine 5.21 to 13.03, fibre 4.2 to
15.05, starch 29.6 to 53.5, ash insoluble in acid 0.06 to 0.62 (long
pepper 1:47), Any larger amount of insoluble ash would probably be
the best indication of a fraudulent addition.
M. J. S.

Detection of Cocaïne Hydrochloride. By M. GOELDNER (Arch. Pharm. [3], 27, 799; from Pharm. Zeit., 34, 471).—The author believes that the following is a characteristic test for cocaïne. 6 or 7 drops of pure, strong sulphuric acid are added to some crystals of resorcinol in a porcelain basin, and the latter is moved to and fro a little, then a little cocaïne hydrochloride is added to the yellow liquid. A somewhat strong reaction follows, and a splendid, blue coloration is immediately obtained; a drop of sodium hydroxide changes this to a lightrose colour. The reaction goes more quickly with powdered resorcinol in place of crystals. Very small quantities of the reagent give no colour reaction. Other alkaloids give nothing approaching to this reaction.

J. T.

Estimation of Indigotin for Commercial Purposes. By F. A. OWEN (Chem. Centr., 1889, ii, 217-218; from J. Amer. Chem. Soc., 10, 178)-1 gram of the substance is weighed on a watch-glass, dried at 100°, finely powdered, rubbed with water to a thin paste, and washed into a 250 c.c. flask. 3 grams of zinc-dust and 6 grams of sodium hydroxide are added, the solution diluted to a little above the mark, shaken up now and then, and after the reaction is complete (during which the solution must remain green, red or brownish streaks indicate that the reduction has been carried too far; a froth indicates the presence of too much zinc), 50 c.c. of the clear liquid is exposed to the air for half an hour, acidified with hydrochloric acid, and filtered through a well-washed filter, dried at 100°, and weighed.

J. W. L.

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General and Physical Chemistry.

Emission Spectrum of Ammonia. By G. MAGNANINI (Zeit. physikal. Chem., 4, 435-440).-The author has determined the positions of a large number of the lines of the ammonia spectrum. These are compared with the lines of Hasselberg's second hydrogen spectrum, with which they show a remarkable coincidence. H. C.

Absorption Spectrum of Nitrosyl Chloride. By G. MAGNANINI (Zeit. physikal. Chem., 4, 427-428).-The absorption spectrum of nitrosyl chloride vapour consists of six absorption bands in the orange and green parts of the spectrum. The wave-lengths corresponding with these bands and their relative intensities are given. H. C.

Electromotive Force of Selenium. By S. KALISCHER (Ann. Phys. Chem. [2], 37, 528).-The author observes that Righi (Abstr., 1889, 555) appears to have misunderstood a remark made by him in a former note (ibid., 3). He had pointed out that selenium cells often give an E.M.F. before exposure to light, and that, therefore, before experimenting on the influence of light on them, they should be tested in the dark to see if they already give any E.M.F. He had no intention of asserting the necessity of actually manufacturing the cells in darkness, and preventing their even being exposed to light before experimenting with them. G. W. T.

Electrical Conductivity of Hydrogen Chloride in Different Solvents. By I. KABLUKOFF (Zeit. physikal. Chem., 4, 429-434).— The conductivity of solutions of hydrogen chloride in benzene, xylene, hexane, and ether is excessively small, that in ether being greatest and that in benzene the least. The molecular conductivity of the solution in ether is found to decrease with rising dilution. Solutions of hydrogen chloride in methyl, ethyl, isobutyl, and isoamyl alcohols have a somewhat greater conductivity. The methyl alcohol solutions have the highest conductivity, being about four times greater than the ethyl and 30 times greater than the isobutyl alcohol solutions. Amyl alcohol, like ether, gives a decreasing molecular conductivity with rising dilution. Hydrogen chloride was also examined in aqueous solutions of ethyl alcohol. The presence of ethyl alcohol is found to greatly decrease the conductivity of hydrogen chloride in water, an addition of 6 per cent. of alcohol causing a decrease of 20 per cent. in the conductivity.

If a solution of benzene saturated with hydrogen chloride is allowed to remain for two or three days, crystals separate out which melt without decomposition, and can be sublimed at high temperature. They are probably of the composition C.H,3HC1. H. C.

VOL. LVIII.

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Electrical Conductivity of Solid Mercury. By L. GRUNMACH (Ann. Phys. Chem. [2], 37, 508-515).-As the result of a further experimental investigation of this subject, the author finds that the apparent resistance of mercury when just melted is 2.5 times its value just before liquefaction begins.

The value 15 formerly obtained by the author (Abstr., 1889, 201) is, therefore, too small. The value now obtained by him is smaller than that given by Cailletet and Bouty, namely 04, and the author attributes the difference between his present and former results, and between both of them and that obtained by Cailletet and Bouty, in great part to the change in volume which mercury undergoes in passing from the solid to the liquid state, and the effects of this change of volume on the resistance, depending as they do on the dimensions of the tubes and their regularity of bore. The degree to which the result is affected in this manner cannot be determined until these changes of volume have been measured, and the author states that an investigation of this point has been commenced.

The results of the investigation described in this paper confirm the conclusion formerly arrived at by the author, that the temperaturecoefficient of decrease of resistance for solid mercury decreases from the solidifying point down to -80°, the lowest temperature at which observations were made.

The values obtained for this coefficient in the former and present series of observations respectively are given below::

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The results of the present investigation therefore confirm the conclusion formerly arrived at by the author, that assuming the truth of Clausius's law expressing the relation between the electrical resistances of simple metals and their absolute temperatures, then mercury must be considered as an exception. G. W. T.

Thermoelectric Currents between Amalgamated Zinc and Zinc Sulphate. By K. A. BRANDER (Ann. Phys. Chem. [2], 37, 457-462). The primary object of the investigation was to determine the relation between the E.M.F. developed and the difference of temperature between the electrodes.

The electrodes, of amalgamated zinc, were placed in two vessels communicating by means of a siphon, and filled with a solution of zinc sulphate. One of these vessels was kept at the temperature of the place of observation, while the temperature of the other was gradually raised.

The author found that, within the limits of errors of observation, the E.M.F. was proportional to the difference of temperature, until this

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