268

The Potash Theory of Scurvy.

and kept in the same dish for twelve hours in a damp | place to absorb moisture. Then add 200 c.c. of cold water to the contents of the dish, collect the precipitated quinon on a filter, and wash, first with pure water, then with boiling alkaline solution, and again with pure hot water, and finally dry.

{CHEMICAL NEWS,

this alkali. There is an opinion that the juice of the lime (Citrus limetta) is stronger and more acid than lemonjuice, but in chemical constitution there is not much difference between the two. Fresh vegetables, as a rule, are rich in potash salts; potatoes, which may be placed at the head, containing no less than 51 per cent in their ash, according to Way and Ogston, and 55 according to Griepenkerl. Grape-juice, which may be considered as the representative of the light wines so largely used in the French and Russian marine, contains in its ash from 60 to 70 per cent of potash, while the husks of grapes have an ash containing 37 per cent. Rice, however, contains only 20 per cent in its ash.

The quinon is now removed from the filter and put into a flask of 500 c.c. capacity, and the small quantity of quinon remaining on the filter paper is washed off with 45 c.c. of hot glacial acetic acid into the same flask. Now heat to boiling and add slowly a solution of 15 grms. of chromic acid in 10 c.c. of glacial acetic acid and ro c.c. of water and boil for four hours. The flask with its contents is kept for twelve hours, then mixed with 400 c.c. of cold water, and again kept standing for three hours. The pre-in cipitated anthraquinon is now collected on a double filter, and washed, first with pure water, then with boiling dilute alkaline solution, and again with pure water, and finally dried at 100° C. until constant in weight. The weight of the quinon obtained is to be calculated in the usual manner into anthracen. The quinon obtained should always be tested for ash, and the weight of the ash deducted from the weight of the quinon before calculating it into anthracen.

A few words about anthracen might be interesting to tar distillers. Some people believe that anthracen showing a low percentage is identical with a low quality anthracen, and that a high percentage anthracen must always be of good quality. This is an error. Some tar distillers push the distillation of the tar or of the anthracen oils too far and they get an anthracen of inferior quality, because it is principally the last portion of the distillate containing the so-called pitch anthracen, which is of inferior quality, and some of the alizarin makers stipulate, therefore, in their contracts "the anthracen must not be made from pitch." My experience is that anthracen of bad quality cannot be improved by simply pressing, and that the quality is not always improved by washing with solvents. But the quality of inferior anthracen is improved (1) if the anthracen in question has not been filtered and pressed by a re-distillation of the same, leaving the last portion as pitch in the still, and (2) if the anthracen has already been pressed by a systematical re-crystallisation from solvents.

THE POTASH THEORY OF SCURVY.

THE discussion which has recently been carried on in the columns of The Times respecting the outbreak of scurvy on board the "Arctic" vessels has recalled to our notice an article published in this journal in 1867 (CHEMICAL NEWS, vol. xv., p. 37), in which we referred to the views of the late Baron Liebig and other high authorities, who held that the value of lime-juice as an anti-scorbutic is due solely to the potash which it contains. It may serve a useful purpose if we reproduce extracts from this article. At any rate they will show the importance of lime-juice being tested by competent analysts :

Lime-juice is used in the English Navy and Merchant Service as an efficient anti-scorbutic. Amongst American seamen scurvy is almost unknown, and this immunity has been ascribed to the very general use of potatoes; whilst in France and Russia the rareness of this disease is simi

larly ascribed to the almost universal consumption of thin light wines as a beverage. Rice, which has been frequently proposed as a substitute for potatoes, has, however, been proved to be utterly valueless as an anti-scorbutic. Again,

the evil effects of salt meat are notorious, but fresh beef alone is capable of preserving health for almost any time.

"These facts are found to agree perfectly with the potash theory of scurvy. The mineral constituents of emon-juice are found to be extremely rich in potash, containing, according to Mr. Witt, upwards of 44 per cent of

"Dr. Garrod, who has examined various kinds of food reference to this point, gives the actual amount of potash contained in different alimentary substances. From this we learn that

One ounce of rice

contains o'005 gr. of potash.

"But without assuming that the active principle of these various anti-scorbutic foods is the potash which they contain, there is no doubt whatever that chemical analysis is abundantly able to show the quality of lime-juice in an accurate and rapid manner. The constituents of limejuice are not many, the organic part contains citric acid, inorganic constituents consist nearly half of potash, and mucus, vegetable albumen, pectin, and sugar; whilst the the rest of the ordinary ingredients of the ash of plants. It is certain that most of these have no action as far as scurvy is concerned, and a little investigation could not fail to show whether the specific consisted of the potash or some other constituent. The work of the analyst would then be to see generally that the article was in a state fit for food and likely to keep, and specially to see that the percentage of the active ingredient did not sink below a certain standard. Too much stress has been laid on the considerable time which it is supposed lime-juice would tively that any juice may be safely pronounced good, bad, take to analyse; and Dr. Leach has stated authoritaor indifferent in from twenty to thirty hours after its receipt by the inspecting officer.' This is far longer than would be required. When once the appliances for such analyses were in working order, we do not hesitate to say that a skilful chemist would supply all the necessary information in a couple of hours.

Assuming, as will most likely prove to be the case, that the potash salts are the specific agents against scurvy, chemical analysis is seen to be indispensable in the selection of anti-scorbutics for use on board ship. It then, however, becomes a question whether the active agent could not be stored and administered with far more economy, ease, and efficacy in the form of some convenient pharmaceutical preparation (such as the granulated effervescing citrate of potash) than when given through the exceedingly unscientific, clumsy, and ofttimes repulsive expedient of serving out lemon-juice to the men. It might also be worth while to ascertain whether the desired end could not be secured by letting chloride of potassium partially replace chloride of sodium in the preservative processes to which the provisions are subjected.

"Whether every sample of lime-juice should be separately examined before shipment, or whether Dr. Stone's sugges tion be adopted of licensing a limited number of limejuice vendors, and occasionally verifying the genuineness of their commodity by analysis, is a matter which need not at present be discussed."

University of London.-The following candidate has passed the recent examination in Public Health :-H. Franklin Parsons, M.D. (gold medal), St. Mary's Hospital.

CHEMICAL NEWS,
Dec. 22, 1876.

}

Experiments on the Radiometer.

PROCEEDINGS OF SOCIETIES.

PHYSICAL SOCIETY.
December 16th, 1876.

Professor G. C. FOSTER, F.R.S., President, in the Chair.

THE following candidate was elected a Member of the
Society-Mr. W. Baily, M.A.

269

attached to a small magnetic needle, and this might be so checked by an external magnet that the strongest light would be incapable of causing the needle and vanes to make a half rotation. If the circumference of the globe be graduated, and the apparatus be brought within the influence of a source of light, the angle to which the needle is deflected will be a direct measure of the intensity of the light, and Mr. Crookes showed that by a simple arrangement such an instrument might be rendered self-recording. Prof. DEWAR exhibited a simple electrometer which he has designed, founded on the discovery of Leipman that the capillary constant is not really independent of the temperature or the condition of the surface, but is a function of the electromotive force. If a capillary tube be immersed in mercury, and dilute sulphuric acid be placed in the tube above the mercury, and a current from a Daniel's cell be so passed through the liquids that the mercury forms the negative pole, the column will be depressed to an extent dependent on the diameter of the tube. In making an electrometer, Prof. Dewar has increased the sensitiveness by connecting two vessels of mercury by means of a horizontal glass tube filled with the metal, except that it contains a bubble of dilute acid. The tube must have an internal diameter of 2 millimetres, and it is essential that it be perfectly clean, uniform in diameter, and horizontal. The instruments exhibited were constructed by Messrs. Tisley and Spiller, and Prof. Dewar showed that it is possible by means of them to measure an electromotive force equal to 1-10,000th of a Daniel's cell; forces capable of decomposing water must be measured by causing two currents to act against each other. The index bubble is brought to zero by uniting the mercury cups by a wire. The apparatus is very convenient, as it requires no preparation, and is extremely simple in its action. He then showed an instrument arranged by Mr. Tisley for producing a current by the dropping of mercury from a small orifice into dilute sulphurie acid. If the vessels containing the mercury and the sulphuric acid be connected by a wire a current is found to traverse it, and Prof. Dewar explained how the electrolysis of water might be effected by this means. He then exhibited a delicate manometer suitable for measuring very slight variations of pressure, and he illustrated the use of it for proving Laplace's law that the internal pressure, multiplied by the diameter of a soap-bubble, is constant. It consists of a U-tube, one arm of which is about 15 inches long, and is bent horizontally, and levelled with great If the shorter arm be connected with a tube on which a bubble has been blown, and the diameter of the bubble be varied, the position of the extremity of the alcohol column will be found to vary in accordance with the above law.

Mr. CROOKES described some of the most recent results he has obtained in his experiments on the radiometer, and exhibited many beautiful forms of the apparatus, most of which have been devised with a view to decide on the correct theory of the instrument. He commenced by describing the arrangement he has used for some time past | in studying the resistance offered by air and other gases to the rotation of a mica disc. It consists of a mica plate suspended by a fibre of glass, and enclosed in a chamber which can be exhausted to any required extent. A mirror is attached to the mica, and the movement of a luminous point reflected from it shows that the decreasing swings form a logarithmic curve, and Mr. Crookes takes the logarithms of the decrements of the swings as a measure of the viscosity of the gas under examination. From the normal atmospheric pressure to the best vacuum which can be obtained by the ordinary air-pump this decrement remains nearly constant, and these experiments have been carried on in vacua of remarkable perfectness, the highest exhaustion obtained being represented by I millimetre on a scale of 10 miles, a point which was attained by means of a Sprengel pump with improvements by Mr. Gimingham, and measured by a McLeod gauge. If the "logarithmic decrement" be represented by 125 at a pressure of 760 m.m., it is not reduced to 70 until the pressure has been reduced to 35-millionths of an atmosphere, and at this point the action of light on a radiometer is at a maximum. On continuing the exhaustion this influence is found to decrease, and Mr. Crookes concludes that in a perfect vacuum the log dec. would not be zero, but about o'or; that is, a mica plate would not continue to oscillate for ever, a fact probably due to the viscosity of the glass fibre. About fifteen different forms of the radiometer were exhibited, and their inventor has satisfied himself that the theory of their action proposed by Mr. G. Johnstone Stoney is the only one capable of completely accounting for their action, and he considers it to be in all probability the correct one. By means of a double radiometer, consisting of two globes of different diameters, and having a wide opening between them, and provided with a four-armed fly which can be made to rotate in either bulb, it has been shown that, other things being equal, the velocity of rotation decreases as we increase the diameter of the bulb. As, on the molecularmovement theory, the rotation is due to a throwing off of particles from the blackened surface of the mica, it follows that, if a piece of transparent mica be attached to each fly in front of the blackened surface, the rotation will take place in the opposite direction, and this proved on experiment to be the case. And, further, when such a plate is placed on either side of the vanes, the motion of the instrument is almost entirely stopped. As these facts can be explained on the "molecular movement or the " evaporation and condensation " theory, Mr. Crookes arranged a radiometer having four transparent mica vanes, and mounted in a rather large bulb. At the side of the bulb a plate of mica, blackened on one side, is so fixed in a vertical plane that the vanes can pass, and when light shines on this fixed plate the fly is found to rotate, a fact which in itself disproves the latter theory. Many other curious forms were exhibited, in some of which the vanes were cup-shaped, as Mr. Crookes has found these to act as well as the ordinary form, a convex surface acting as though it were blackened. In conclusion, he exhibited a photometric four-vaned radiometer, in which the fly was

care.

DEUTSCHE CHEMISCHE GESELLSCHAFT,
BERLIN.

November 27th, 1876.

Prof. A. W. HOFMANN, F.R.S., President, in the Chair.

F. WÖHLER, "Action of Palladium in an Alcohol Flame." Palladium held in an alcohol flame is rapidly covered with carbon. The author supposed this to be due to its affinity for hydrogen, but finds by experiment that palladium does not decompose ethylen and the various gases of the alcohol flame below a red heat, although below the decomposing temperature of ethylen. He suggests the possibility of a temporary absorption of hydrogen, as in the case of copper heated in ammonia gas.

E. BAUMANN," Synthesis of Hydrogen-Phenyl-Sulphate and its Homologues." This compound, which the author discovered in urine, is easily obtained by the action of pyrosulphate of potassium, K2S2O7, on a concentrated aqueous solution of potassium phenylate. Corresponding compounds of cresol and resorcin are obtained in a similar way.

270

Deutsche Chemische Gesellschaft, Berlin.

CHEMICAL NEWS,
Dec. 22, 1876.

H. WILLGERODT, "Action of a-Dinitro-chloro-benzol the latter's property of forming compounds similar to upon Acetamide. The two alone give no reaction at a hydrogen-phenyl-sulphate on entering the animal ortemperature of 150°, but upon addition of magnesia ortho-ganism. Substituted phenols possessing the character of para-nitraniline is obtained. The reaction with acetamide an acid do not, however, show this reaction.

is much more difficult than that with oxamide.

P. HUNAUS, "On Citric Acid and Aconitic Acid." In the course of investigations upon the constitution of citric acid the following compounds were obtained :-Trimethylcitrate, C9H1407, by the saturation of an alcoholic solution of citric acid with gaseous hydrochloric acid, triclinic crystals melting at 79°; acetyl-trimethyl-citrate, by treatment of the preceding compound with acetyl-chloride, a colourless liquid boiling at 280°; and trimethyl-monochloro-tricarballyate, C9H13C1O6, obtained by the action of phosphoric pentachloride upon the first compound, a heavy colourless oil; heating changes it into trimethylaconitate. Aconitic acid he obtained easily in large quantities by first leading gaseous hydrochloric acid into citric acid at a temperature of 140°, dissolving in a little water, evaporating to dryness, and then following the customary method.

H. WILLGERODT, "Action of a-Dinitro-chloro-benzol upon Carbamide." The reaction has been studied under a great variety of circumstances in the attempt to introduce the dinitro-phenyl radical into carbamide. In all cases, however, dinitraniline (melting-point 180°) has been obtained, and the carbamide has been completely decomposed. L. F. NILSON, "Plato-nitrites and Diplato-nitrites." The author has studied the double nitrites of platinum monoxide and the metals. He regards these compounds as containing the radical (PtO2(NO)4, which he terms plato-tetra-nitrosyl. The acid previously regarded as acid nitrite of platinum is plato-nitrosylic acid, and the salts plato-nitrites. With some metals he has obtained diplato-nitrites, containing the radical Pt2O3(NO)4. Salts have been prepared with thirty various metals. These salts are generally obtained as fine crystals, are as a rule A. MICHAEL and T. H. NORTON, "Preparation and Proeasily soluble in water, and not decomposed at 100°. perties of Tri-iodo-resorcin." Iodine monochloride added Beryllium, iron, and indium form diplato-nitrites only. to a cold aqueous solution of resorcin gives an insoluble ALBERT ATTERBERG, "Derivatives from a-Dinitro- precipitate of tri-iodo-resorcin, C6HI3(HO)2. The crysnaphthalin and B-Dinitro-naphthalin." From a-dinitro-tals obtained from a solution in alcohol or carbon disulnaphthalin the following compounds have been prepared:- phide melt at 145°, and are changed by nitric acid into dinitro-y-dichloro-naphthalin, C10H4C12.2NO2; chlor- styphinic acid, C6H(HO)2(NO2)3. The reaction is somenaphthylamin-hydrochlorate, CroH6CI.H2N.HCI; chloro- what uncommon. Treatment of pyrogallic acid with naphthylamin-sulphate, C10H6C1H2N.H2SO4; and chloro- iodine monochloride gives no results. naphthylamin, CroH6Cl.NH2. B-dinitro-naphthalin on treatment with phosphoric pentachloride yields large quantities of d-trichlor-naphthalin, with a small amount of a new dichlor-naphthalin, which receives the distinctive mark. The properties of d-trichlor-naphthalin have been thoroughly examined, and the compound changed into a dichloro-phthalic acid, showing that only two of the three chlorine atoms are upon the same half of the naphthalin molecule.

A. ATTERBERG, "On the Constitution of some Naphthalin Compounds." A consideration of the positions in the naphthalin molecule of doubly- and trebly-substituted chlorine derivatives.

KARL HEUMANN, "Apparatus for the Representation of the Manufacture of Sulphuric Acid." A description of an ingenious arrangement for a lecture experiment.

W. THÖRNER," Derivatives of Para-tolyl-phenyl-ketone." By the treatment of para-benzoyl-benzo-trichloride, C6H5-CO-C6H5-CC13, resulting from the action of chlorine upon para-tolyl-phenyl-ketone; with phosphoric pentachloride oxygen is replaced by chlorine, and a ketone pentachloride obtained. The rest of the paper is occupied with theoretical considerations upon the structure of the two isomeric benzo-pinacolins resulting from the reduction of para-tolyl-phenyl-ketone, and accounts of experiments undertaken with this object in view. To a-pinacolin he assigns a formula analogous to that of pinacon, while pinacolin is regarded as being similar in structure to the pinacolins of the fatty series.

OTTO FISCHER, "On the Phthaleins of Tertiary Aromatic Bases." The author has obtained dimethyl-anilinephthalein by the action of phosphoric anhydride or other dehydrating bodies upon a mixture of dimethyl-aniline and phthalic anhydride or phthalic chloride. It is of a deep green, soluble in most dissolving agents, and possesses all the properties of a colouring principle. With hydrochloric acid, picric acid, &c., it forms two series of salts, the green ones containing one molecule of acid, and the yellow two molecules. By reduction, as in the case of phenol phthalein, two atoms of hydrogen are taken up, and another new base, giving well defined salts, is obtained. Other tertiary compounds, such as methyl-diphenylamine, yield also, by the above reaction, green colouring matters.

W. STAEDEL and L. RUGHEIMER, "On the Action of Ammonia upon Chlor-acetyl-benzol." Two compounds result from this reaction, both possessing the formula C16H13O2Cl. The first melts at 117°, and is easily oxidised, yielding benzoic acid. The second melts at 154°, is more insoluble than the first, and is oxidised with greater difficulty, yielding another aromatic acid as well as benzoic acid.

T. ZINCKE, "Action of Dilute Sulphuric Acid upon Hydrobenzoin and Iso-hydrobenzoin: on Pinacone and Pinacoline." Hydrobenzoin and iso-hydrobenzoin give each with sulphuric acid a liquid and a solid crystalline B-compound. Both of the liquids were found to consist of the aldehyd of diphenyl-acetic acid. The solids possess alike the formula C14H12O, have different physical properties, but identical chemical properties. From theoretical considerations the author regards these bodies as the same compound in different physical conditions, and views hydrobenzoin and iso-hydrobenzoin as identical, explaining their differences in the same manner, and placing them in the class of pinacones.

H. BRUNNER, "Preliminary Notice on the Action of Silver Nitrite upon Iodo-benzyl, of Silver Nitrite and Potassium Nitrite upon Chlor-benzyl, and of Silver Nitrate upon Chlor-benzyl." The results obtained are as yet of no particular value.

R. v. D. VELDEN and E. BAUMANN, "Action of the Turpentines upon Animal Organisms." Numerous experiments A. BLATZBECKER and T. ZINCKE, "On Benzyl-isoshow the falsity of the statement that pure oil of turpen-phthalic Acid." This acid, C6H5C6H3(COOH)2, is obtine, and bodies belonging to the same class, form com- tained from benzyl-isoxylol by oxidation with potassium pound ethers with the sulphuric acid present in animal bichromate and sulphuric acid. It melts at 278°. Various organisms. Previous statements upon this subject are salts and ethers have been prepared. By reduction with probably due to the fact that the turpentines experimented zinc and hydrochloric acid benz-hydryl-isophthalic anhyupon were not free from essential oils, or such substances dride is obtained, C15H10O4. Sodium amalgam gives the as thymol, containing oxygen, and entering easily into dibasic benzyl-isophthalic acid, C6H5CH2.C6H3.(COOH)2. combination with sulphuric acid. L. KLIPPERT AND T. ZINCKE, "On Para-Xylenic Acid." The authors have obtained from para-dichlor-xylol, by means of the dicyanide para-xylinic acid, C6H7(CH2COOH)2.

E. BAUMANN and E. HERTER, "Action of the Homologues of Phenol upon Animal Organisms." The various cresols, thymol, resorcin, and other homologues of phenol, possess

Deutsche Chemische Gesellschaft, Berlin.

It yields easily crystallisable salts and ethers, a number | finds glass of the following composition best suited to of which have been prepared. resist the decomposing influence of steam

C. LIEBERMANN and M. WALDSTEIN, "Emodin from the Bark of the Rhamnus frangula." An examination of the acid in the bark of the Rhamnus frangula, termed by its discoverer, Faust, frangulic acid, shows it to be identical with emodin, C15H10O5. This new source of emodin allows of its being produced much more cheaply and easily than by the method now in use.

C. LIEBERMANN, "Constitution of Oxythymo-quinon." From the comparison of numerous closely related compounds in the naphthalin group, the author condemns the formula of Ladenburg in his lately issued work on "The Theory of the Aromatic Compounds."

C. BÖTTINGER," Action of Zinc-dust on the Chlorides of Sulpho-para-bromo-benzoic Acid." This reaction yields a mixture of the following four compounds, the separation and purification of which are attended with great difficulty:-Sulphi-para-bromo-benzoic acid,

crystallises in fine needles, and is decomposed by heating. Sulphi-bromo-benzaldehyd, C6H3Br(COH)(SO2H), has an odour similar to that of the oil of bitter almonds, and melts at 131°. Hydrosulph-bromo-benzaldehyd,

and hydrosulph-bromo-benzoic acid, C6H3Br(COOH)(SH), are both easily decomposed.

B. ARONHEIM, "On the Use of Molybdenum Pentachloride for the Production of Organic Chlorides." The joint action of this body and chlorine gas is the same as that of antimony, penta-chloride, and chlorine, forming with organic bodies highly chlorinated compounds; carbon disulphide, for example, is changed into carbon tetrachloride. It also serves admirably for the substitution of chlorine for hydrogen in benzol when the latter contains likewise substituted hydrocarbons which it is desirable to leave intact.

B. ARONHEIM, 46 Synthesis of Tolyl-butylen." This compound, (CH3.C6H4)CH2.C3H5, one of the few nonsaturated hydrocarbon substitution derivatives of benzol, is obtained from the action of allyl-iodide and sodium upon meta-xylyl-chloride. It is a colourless oil, boiling at 195°, and forming addition compounds with the halogens.