sealed tubes at 150° for several hours with excess of triethylamine. The product is treated with an aqueous solution of potassium carbonate, and the oily drops of the liberated alkaloïd are dissolved in ether-alcohol, and purified by treatment with animal charcoal. When mixed with auric chloride, it yields the modified aurochloride of pilocarpidine, AuCl3,C10H1N2O2, melting at 144°.

In order to convert pilocarpidine into pilocarpine, the extra-pyridic nitrogen of the former must be rendered pentavalent by the addition of a methyl-group, whilst the pyridic nitrogen remains trivalent.

When pilocarpidine is mixed with methyl iodide in alcoholic solution at 60-100°, it combines with 1 mol. of methyl iodide, forming a compound which crystallises with difficulty. If this compound is mixed with auric chloride an oily precipitate is formed and gradually changes to large prismatic needles which melt at 152-153° and have the composition AuCl,Me, CoHN2O2. This compound readily loses methyl chloride when fused, and yields modified pilocarpidine aurochloride, melting at 144°. Pilocarpidine mixed with excess of methyl iodide in concentrated methylic solution, and then with fragments of solid potassium hydroxide, care being taken that the temperature does not rise too high, combines with methyl iodide (1), and methyl hydroxide (2), and if this product is treated with carbonic anhydride, and the liberated alcohol removed, a methiodide is obtained identical with that formed by the action of methyl iodide on pilocarpidine at 60°. The hydroxymethylpilocarpidine obtained by the action of silver oxide on the corresponding methiodide, yields pilocarpidine when boiled with water. These results show that it is difficult if not impossible to remove the methyl hydroxide from position (1), and replace it by methyl hydroxide in position (2).

When, however, pilocarpidine methiodide is oxidised by means of silver permanganate, an unstable group, MeN().MnO,, is formed, and decomposes without affecting the remainder of the molecule. aqueous solution of pilocarpidine methiodide is mixed with silver permanganate until the greater part of the silver iodide is precipitated. Oxidation takes place immediately, and the liquid contains pilocarpine and formic acid. The alkaloïd is liberated by addition of potassium carbonate, and yields the aurochloride AuCls,CHNO2, melting at 88°. Synthetical pilocarpidine and pilocarpine yield gummy derivatives similar to those obtained by Harnack and Meyer from the natural products. This phenomenon is confined to the gold compounds, and is purely physical.

The physiological action of synthetical pilocarpine is identical with that of the natural alkaloïd. C. H. B.

Physiological Chemistry.

Relation between Muscular Activity and the Chemical Effect of Respiration. By M. HANRIOT and C. RICHET (Compt. rend.. 105, 76-79).-The work done consisted of raising a weight of 18 kilos. to a height of 0.5 metre several times, the air expired during the

process being collected and measured. The oxygen absorbed was less than that evolved in the form of carbonic anhydride, and the quantity of carbonic anhydride over that originally existing in the air was equal to 4.5 per cent. of the expired gas. This is the limit towards which the proportion of carbonic anhydride in the expired air tends when work is being done. Correcting for the work done in raising the arms and other bodily movements, it was found that ten lifts or 95 kilogrammetres correspond with the absorption of 0.301 litre of oxygen, the evolution of 0.401 litre of carbonic anhydride, or in round numbers, to do work equivalent to 100 kilogrammetres requires the inhalation of 11 litres of air above the normal volume, the absorption of 0-300 litre of oxygen, and the evolution of 0.400 litre of carbonic anhydride. The ratio between the oxygen absorbed and the carbonic anhydride evolved, shows that the chemical change involved is more complicated than the simple oxidation of glucose or glycerol. Assuming that the energy is provided by the combustion of glucose, the 0-8 gram of carbonic anhydride evolved is equivalent to 0.545 gram of glucose, which corresponds with 2:05 cal. or 860 kilogrammetres. The work actually done was 95 kilogrammetres, and hence the efficiency of the human machine is one-ninth. Taking the oxygen absorbed as the basis of calculation, and assuming that it is all used in the combustion of glucose, it corresponds with a development. of heat equivalent to 645 kilogrammetres, and hence the efficiency in this case is oneseventh. C. H. B.

Heat Developed by the Activity of Muscles. By A. CHAUVEAU and KAUFMANN (Compt. rend., 105, 296–301).-The temperature of the muscles of the jaws of a horse was taken by a thermoelectric method, fine needles being inserted one into the left muscle the other into the right muscle. So long as the muscles remained at rest the scale of the galvanometer remained at rest, but when the muscles were active the galvanometer needle began to oscillate. The enervation of one muscle does not affect the relative temperature whilst in repose, but when in action the temperature of the muscle which performs its functions rises. Cooling by radiation and evaporation is prevented by a casing of cotton-wool. The heat developed is calculated from the weight and temperature of the muscle and the quantity of blood which traverses it. The rise of temperature when the muscle is engaged in mastication is 042, but when the muscle makes the same movements without doing any work the rise of temperature is 0 47, or the work done corresponds with a rise of temperature of 0.05°. It is evident that a very considerable amount of heat is developed when a muscle is in operation, but only a small part of this energy (one-seventh or one-eighth) is used up in doing useful work. C. H. B.

Action of Micro-organisms from the Mouth and from Fæces on Food-stuffs. By W. VIGNAL (Compt. rend., 105, 311-313).— The 19 organisms isolated from the mouth exert very considerable digestive and fermentative action. Many of them dissolve albumin and fibrin, curdle milk, invert saccharose, ferment glucose,

and saccharify starch. Many of them resist the action of the gastric juice, pancreatic juice and bile.

The fæces contain an enormous number of microbes, including at least 10 species, six of which are also found in the mouth. The other four possess digestive and fermentative powers.

These organisms play a very important part in digestive changes, and there is little doubt that these changes are of a much more complex character than is generally supposed. C. H. B.

its

Sugar in Urine. By C. MÉHU (J. Pharm. [5], 16, 145-149).— The author has frequently proved the presence of small quantities of sugar in the urine of persons passing albuminous urine after a longer or shorter course of milk food. The observations have only been made in the cases of patients whose urine was absolutely free from sugar before the milk treatment was commenced. It is only very rarely that the sugar has amounted to 4 grams per kilo. of urine, usually not more than 2 grams occurs. The urine is acidified slightly and boiled to coagulate albumin, filtered, and treated with volume of basic lead acetate, filtered, and freed from lead by sodium carbonate. The resulting liquid added to its own volume of recently prepared Fehling's solution is heated for 10 minutes in boiling water; the reduction is very evident if sugar is present. The urine must be recent and non-ammoniacal. Preliminary concentration of the liquid at a moderate temperature to one-third its volume favours the reaction. Instead of Fehling's solution, the author has also used a solution of bismuth prepared as follows:-Bismuth subnitrate, 15.3 grams; tartaric acid, 30 grams; soap lye, 360 grams, or fused sodium hydrate, 80 grams. The soap lye is gradually added to the powdered mixture of the two first substances and the volume is made up to 500 c.c. with hot water. The solution is filtered and can be easily preserved. 1 e.c. is added to 10 c.c. of urine and the mixture heated to boiling, or better still heated in a boiling saturated salt solution. If the mixture does not blacken in about 10 minutes, it is concluded to be free from sugar. This reagent does not blacken in contact with uric acid or pure calcium oxalate. It is more certain than Fehling's solution but somewhat less rapid. It is absolutely necessary that the liquid to be tested should be free from albumin and albuminose, or a black precipitate of bismuth sulphide results. In all cases, it is well to filter the liquid before applying the test.

J. T.

Per-ruthenic Acid in Histology. By L. RANVIER (Compt. rend., 105, 145-147).-Per-ruthenic acid is more readily reduced by animal tissues than is osmic acid, but the action is so energetic that no differences are observed in the behaviour of different kinds of tissues, all becoming equally black.

C. H. B.

Chemistry of Vegetable Physiology and Agriculture.

Microbe of the Indigo Fermentation. By E. ALVAREZ (Compt. rend, 105, 286-289).-In the fermentation of the indigo plant, the colouring matter forms on the surface of the liquid that is in contact with the air, and the fermenting liquid contains an enormous number of bacilli and micrococci which can be isolated and cultivated by the usual methods. A sterilised solution of the indigo plant will not ferment. The fermentation is due to one bacillus alone and is not produced by any other. It is about 3u long and 15μ broad with rounded extremities, and groups of six, eight, or more are frequently arranged end to end in the form of a chain. The bacillus is surrounded by a capsule like the bacilli of pneumonia and rhinoscleroma. It is readily cultivated by the ordinary methods, and when placed in an infusion of the plant, indigo is formed, and the bacilli become stained blue and rapidly multiply. The microbes of pneumonia and rhinoscleroma also determine the fermentation of indigo. Other pathogenic microbes produce no effect. The indigo bacillus is strongly pathogenic. When injected subcutaneously, it produces only local effects, but when injected into the veins or any of the more vascular organs, such as the lungs, of the guinea-pig it rapidly causes death. The principal effects are congestion of the digestive tube and strongly marked lesions of the excretory organs. C. H. B.

Aleurone-grains in the Seed of Myristica Surinamensis. By A. TSCHIRCH (Arch. Pharm. [3], 25, 619–623).-The seeds are peculiar in the extraordinary development of the albumin crystalloïds of the aleurone-grains. Each cell is almost filled with a large crystalloid of the hexagonal system, either a rhombohedron (R) or a combination of the same with the basal plane (R·OR). Twin forms are rare. These crystalloïds form the matrix of very large aleuronegrains. As a rule, to each crystalloïd is attached a greater or less number of globoïds, each including a needle-shaped crystal of calcium oxalate. Besides the globoïds, the oxalate crystals, and the proteincrystalloids, the aleurone-grains also contain a residue of amorphous substance. To separate these constituents, a section is freed from fat by means of ether, then very dilute aqueous potash dissolves the albumin crystalloids after washing, acetic acid dissolves the globoïds, and then the calcium oxalate is dissolved in dilute hydrochloric acid.

J. T.

Examination of Caucasian Madder Root. By O. BERGAMI (Ber., 20, 2247-2251).-The dried powdered root was extracted with boiling absolute alcohol, and the extract reduced toto of its bulk by distillation; a yellowish-brown, crystalline substance separated, consisting of crude glucosides. By further evaporation, crystals of cane-sugar were obtained; the mother-liquor from these were treated with water to precipitate the colouring matter present. The method employed in purifying the glucosides is described. The yield

of pure ruberythric acid is 0.1 per cent. of the weight of root. The amount of cane-sugar is about 3 per cent. The pure colouring matter, which consists of alizarin together with much purpurin, amounts to about 6 per cent. of the weight of root. N. H. M.

Experiments with Ensilage in Holland. By H. THIEL (Bied. Centr., 1887, 445—447).—After allowing the grass to make for a day, it was formed into heaps 10 m. square, the outer portions being higher than the inner, whereby a more even mass is produced, the top was then covered with boards, and weighted with stones to 500 kilos. per square metre.

The composition of the ensilage compared with that of some of the same grass made into hay was as follows:

Ensilage in 300

parts corresponding
with 100 parts hay.

Six milch cows and six heifers were then fed on the hay and ensilage, in addition to other foods including roots and linseed cake. It was afterwards found that those heifers and cows fed with hay increased in live-weight to a greater extent than those fed on the ensilage, the increase being 104 and 64 per cent. respectively. The yield and quality of milk was, however, best from those cattle fed on ensilage. The editor of the Centralblatt considers that this last fact is due more to the individuality of the cows than to the ensilage.

E. W. P.

Analytical Chemistry.

A Source of Error in Gas Analysis. By W. HEMPEL (Ber., 20, 2344). The author points out that cuprous chloride absorbs gases of the ethylene series, but that when such solutions are further brought in contact with carbonic oxide, varying quantities of the hydrocarbons are again evolved. In analyses in which cuprous chloride is used as an absorbent for carbonic oxide, it is therefore necessary first to remove the heavy hydrocarbons. L. L. T.

A Gas-burette which is Independent of Atmospheric Pressure and Temperature. By W. HEMPEL (Ber., 20, 23402343). As in Petterson and Palmquist's apparatus (this vol., p. 999) the influence of atmospheric temperature and pressure is obviated by