QUININE SUBSTITUTES.

IN our last Number we gave an abstract of the very interesting paper read by Mr. Markham before the Society of Arts, on the "Introduction of Chinchona Plants into India." The facts contained in it lead us to suppose that the anticipated quinine famine will not be so severe as most people have appeared to think. At the same time, there is a period of at least ten years to pass through before we can hope to obtain chinchona barks in any quantity from their new country. Bark merchants shake their heads and sigh dolefully when they are questioned about the prospects of the bark trade during the next decade. The mischief that would result from a bark famine, not merely to our colonies, but to our hospitals and dispensaries at home, is fearful to think of. As it is, Dr. Chambers assures us that many institutions have been compelled to discontinue the use of quinine altogether, on account of its dearness. At the same time, the Registrar-General tells us that febrile maladies are on the increase. What, then, is to be done? Looking at the matter from a scientific point of view, there appear to be three remedies applicable to the case-1. The use of the salts of chinchonine. 2. The discovery of the method of making quinine artificially. 3. The successful substitution of this febrifuge by some other organic compound, natural or artificial.

The first remedy is perfectly applicable for the present only. Our largest chinchona alkaloid manufacturers, Messrs. Howards, introduced the hydrochlorate of chinchonine to the medical profession at the late International Exhibition at a comparatively low price, and, in spite of the well-known conservative principles of certain members of that body, they have since manufactured and distributed large quantities of this alkaloid and its salts over all parts of the world. But the low price of chinchonine cannot be expected to continue. Some years since, we recollect that the same firm introduced quinidine into the market at a low rate, but the demand soon rose above the supply, and quinidine went up nearly to the price of its brother, quinine. We fear greatly that the same thing will occur with the last valuable addition to our stock of febrifuge alkaloids. It is, however, a remedy for the present, and should be well tried and reported on by those who are competent to do so. The second remedy-the discovery of the method of forming quinine by synthesis-should be again sought for. In 1856, Mr. W. H. Perkin endeavoured to form this alkaloid artificially by oxidising allyl-toluidine with bichromate of potash; but instead of discovering quinine, he discovered aniline purple, the magnificent golden reflection of which so dazzled his eyes, that he naturally gave up his search for the healing alkaloid. Since that period neither the talented chemist just named, nor any other of our vast army of workers in organic chemistry, appears to have taken up the subject. The discovery of the third remedy

seems to be closer at hand. Amongst the vast number of natural organic bases, how few are there that have received proper trials as to their therapeutic qualities! Phloridzin, esculin, salicin, and some half-dozen more, have been partially tried at various times, and are said, in certain pharmacological works, to be febrifuges; but we have little information about them that is to be relied on. All of them are, however, to be easily obtained and experimented upon. But the largest field open to the ambitious, would-be discoverer of the substitute for quinine, seems to us to be amongst the innumerable artificial organic bases, acids, and neutral products that are being discovered daily in almost every laboratory in the world. The members of this vast group of substances that have received attention at the hands of therapeutists may be reckoned on the fingers of one hand. Propylamine has been experimented on by Avenarius, in Russia, and by Procter, in America, who state that it is a valuable curative agent in cases of chronic rheumatism. Picric acid has been tried as a febrifuge by Braconnot, but it dyed the unfortunate patients a brilliant yellow, and was consequently objected to by them. There is but little doubt that pharmacy generally would receive important benefits from the systematic study of some of these compounds, but our physicians are but seldom chemists, and our chemists are too fond of either purely scientific investigations, or of making researches into artificial dyeing materials. Surely we have dyes enough to go on with for a few years; and as to new compounds, we have not yet discovered the properties of a thousandth part of those whose names we glibly use every day. Far be it from us to take a utilitarian view of chemical research. we must never forget, while admiring as we do the magnificent discoveries in pure chemistry that are taking place daily, that one of the noblest aims of our glorious science is the discovery of substances that may administer to the wants and enjoyments of our fellows, that may bring health and ease to the writhing sufferer, or that may restore the dying patient to life and strength.

But

The experience of the last ten years has shown that therapeutists are fully alive to the importance of practising their art on scientific principles; let them now, therefore, show their proper appreciation of the truths of chemical science by aiding their chemical brethren in testing to the utmost some few, at least, of the organic products formed in the laboratory. At first, no doubt, the work would be purely experimental, but gradually the experience gained would soon show from what class of products successful results might be expected. While botanists are ransacking the fields and forests of the world in search of new remedies, it will be surely a disgrace to the scientific chemist if no results are obtained from the use of substances of more definite composition which may easily replace the thousand and one medicaments with pseudo-scientific names, so puffed and advertised in every direction.

CHEMICAL NEWS,

May 2, 1863.

action has been maintained.

The dark mass is a mixture of several substances; it partially dissolves in water, leaving a more or less solid resin. The water solution gives with potash an oily precipitate, containing a considerable portion of the aniline unaltered. When this precipitate is boiled with weak solution of potash, the aniline distils over, while a viscid oil remains, which gradually solidifies with a crystalline structure. By washing this residue with alcohol, and crystallising it several times from boiling alcohol, it is rendered perfectly white, and there remains in solution a very soluble substance, of a magnificent

crimson colour.

That portion of the dark mass which is insoluble in water dissolves very readily in hydrochloric acid, and is reprecipitated by alkalies in the state of an amorphous powder of a red colour, soluble in alcohol, which it colours a rich crimson. The greater part of this colouring substance is the same as that accompanying the crystalline substance.

In the early part of the following year, Messrs. Renard, Frères, of Lyons, applied for and obtained a patent for improvements in the "Preparation of Red Dyes,"† consisting in the production of a new dye (which they call "fuschiacine," from the resemblance of the colour to that of the fuschia), by heating together aniline and anhydrous bichloride of tin to the boiling point, and boiling the mixture for fifteen or twenty minutes.

In the place of bichloride of tin may be substituted bichloride of mercury, perchloride of iron, or protochloride of copper, but no proportions are given as proper to be used in any case.

The remainder of the specification relates to the separation and purification of the colouring substance. Messrs. Renard have lately taken proceedings against other manufacturers of this dye, and have claimed the sole right of producing it. They also obtained a judgment in their favour last August, the effect of which was to give them a monopoly of this manufacture.

In the trial of this case it was argued that the prior publication by Dr. Hofmann of the fact that a red colour was obtainable from aniline did not affect the claim of

• Comptes-Rendus, xlvii.

↑ Specification, No. 921, April 12, 1859.

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Messrs. Renard, inasmuch as that fact was merely an accidental result of laboratory experiment, and also because the mode of production adopted by him could not be employed in practice in consequence of its being extremely dangerous to the operator.

The "Société Industrielle " of Mulhausen have taken up this subject, with the view of inquiring into the reality of these objections to the production of aniline red by means of bichloride of carbon, and, as the result of experiments, they have come to the conclusion that this mode of producing aniline red is neither dangerous nor impracticable.

They found that pressure is not a necessary condition of the reaction, but is requisite only for the purpose of preventing the escape of the bichloride of carbon or aniline, and, that in place of applying pressure to the mixture while it is being heated, an equally good result may be obtained by using a condenser, which will admit of the condensed vapour flowing back again into the vessel in which the mixture is heated. In conducting bichloride of carbon with three times its weight of this experiment the flask containing the mixture of aniline was kept at a temperature between 130° and 135° C. for one and a-half to two hours, during which time there was a slight reaction perceptible, and the volatilisation of the bichloride ceased. The flask was then heated to 170 or 180° C. for one and a-half to two After cooling, a solid blackish brown mass remained. This hours, and during this time the liquid became thicker. solution, containing much hydrochloric acid and hydrowas treated with boiling water, and yielded a very acid chlorate of aniline, and some of the colourless crystalline base described by Dr. Hofmann.

containing alkali gave a nearly colourless solution, Further treatment of the mass with boiling water which, after being filtered, evaporated, and neutralised with an acid, was converted into a deep red coloured liquid that dyed floss silk deep crimson.

with alkaline solution contained but very little colouring The resinous residue remaining after this treatment

substance.

of Messrs. Renard has been appealed against, and the In consequence of these results, the decision in favour case will be tried again. The question raised is one of especial interest to patentees. Messrs. Renard appear to claim, not merely a method or methods of producing a red dye from aniline, but also the conversion of aniline into a red dye, by bringing about a certain change by any means whatever. Such a claim as this naturally shuts the door to any possibility of obtaining patents for improvements in the mode of manufacturing the red dye, which could be worked independently of Messrs. Renard's under licences for the production of the red dye from patent. Any such improvements could only be practised aniline. In very many cases it would only be justice to an original inventor that his patent should have such an application, nor would it be any injustice to the inventors of improvements in the details or methods of manufacture; red dyes from aniline, any improvements in the mode for to take the case of the production of of effecting this derives its value in great measure from the original discovery that such a production of red dye from aniline is possible, and the practice of those improvements should be subject to a royalty to the original

discoverer of that fact.

But before such a title can be justly established, it must be satisfactorily shown that the original discovery was protected by a patent, and was made by the patentee, who claims to exercise a prior right over the inventor of

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improvements, and to participate in the profits arising from those improvements. In the case of the production of red dye from aniline, it does not appear that Messrs. Renard are in a position to establish this title. The discovery of the fact that a red substance was obtainable from aniline was not made by Messrs. Renard, but was made prior to the date of their patent by Dr. Hofmann. Moreover, it was not made the subject of a patent, but was publicly announced. It is true the announcement of this fact by Dr. Hofmann was not accompanied by any reference to the application of the colour-substance to dyeing; but even in this case the fact of such a substance being obtainable was so far made public property, that it was placed beyond the power of any one who afterwards applied the substance to dyeing to claim a monopoly in that application other than that which might belong to the mode of producing

the colour.

Messrs. Renard appear, indeed, to have admitted this view of the matter to be correct by their endeavour to prove that the production of the red substance from aniline by Dr. Hofmann was not capable of being carried out practically according to the method he adopted. There can be no doubt, however, that if Dr. Hofmann had taken out a patent for the production of a red colour from aniline by means of bichloride of carbon, that he would have been fairly entitled to a monopoly in the production of this colour, and to have claimed a royalty from other inventors of improved methods of producing this colour by means of reagents analogous in their nature and mode of action to bichloride of carbon.

In the presence of such a patent, too, the use of bichloride of tin as a substitute for bichloride of carbon might even have been regarded, not as an actual improvement, but as a colourable imitation. The objection that bichloride of carbon is not an article of commerce, or sufficiently easy to obtain for the purpose of manufacturing dyes, would not be of much weight, for the value of the results obtainable by its use must be taken into account before this objection could be maintained. The same objection might have been made to the use of aniline for the production of dyes, on account of its being a substance known only in the chemist's laboratory as an object of scientific research. The fact of any substance being only so known is, however, no argument against its being serviceable in manufacturing industry. It is the application, or the use of which it is susceptible, and the demand created by its use, that determines whether or not such a substance is to be regarded as belonging to science or to industry.

PHYSICAL SCIENCE.

On the Long Spectrum of Electric_Light," by G. G. STOKES, M.A., D. C.L., Sec. R.S., Lucasian Professor of Mathematics in the University of Cambridge.

(Continued from page 200.)

Arc Discharge, and Lines of Blue Negative Light. On diminishing the distance between the electrodes, formed suppose of copper wires, the brightness of the metallic lines at first improves, and after wards changes but little, or, if anything, rather falls off. On still further diminishing the distance, so that the electrodes almost touch, and the discharge passes with little noise, a new set of strong lines make their appear ance in the invisible region of moderate refrangibility.

* Abstract from the Proceedings of the Royal Society.

CHEMICAL NEW, May 2, 1863.

In this mode of discharge, in which the negative electrode, if at all thin, quickly becomes red-hot and fuses, the jar has not much influence, and the lines in question are still better seen when it is suppressed altogether. To show them to perfection, it is best to take a flat negative electrode, so as to carry off the heat, and not to hide from the prism any part of the blue negative light, and a sharp positive electrode almost touching the former. In this way the visible discharge is reduced almost wholly to an insignificant-looking star of blue light; but it is wonderful how strong an effect it is capable of producing in the invisible region. The most striking part of the invisible spectrum consists of four bright lines situated not far from the visible spectrum. These are followed, after a nearly dark interval, by light arranged in masses resembling in its general aspect the groups of copper lines (from which, however, it differs), but not strong enough to be resolved or accurately measured. There are also a couple of blue bands seen by projection. These are not seen on looking at the blue light directly with a flint-glass prism of 60°, because everything is seen in too great detail. Most of the air-lines in the invisible spectrum, especially the bands beyond line 4, have an ill-defined look, and would probably be resolved did the intensity of the light permit.

The appearance just described is independent of the nature of the electrodes, and therefore is to be referred to the air, and not to the metal. On viewing in a moving mirror the star of light producing this effect, it is found to have a considerable duration.

On slightly separating the electrodes, forming an image of the discharge with the 2.5-inch lens, and receiving it on a cake of the uranium salt, a very strong fluorescence was seen over the image of the blue disc when the lens was focussed for a point a little beyond the visible spectrum. On moving the lens onwards, the fluorescence produced by the rays belonging to this image spread out into a ring; and on moving still further, a tolerably well-defined image of the whole discharge was perceived. Of this the part belonging to the blue disc was the brightest, and was surrounded concentrically by the ring before mentioned, now still further widened. The image of the remainder of the discharge was brightest where it was most contracted at the positive electrode, The discharge generally was perhaps of slightly higher refrangibility than the blue disc, even excluding from the latter the rays belonging to the ring. It thus appears that the four bright lines figured were produced mainly by the blue negative light.

The mode of transition of the discharge may be studied by placing the electrodes at the greatest strikingdistance and making them gradually approach. At first there passes a clean bright spark making a sharp report, and not resolved by a revolving mirror. The invisible spectrum which this shows is too faint for precise observation; the visible spectrum shows chiefly air-lines. As the electrodes approach, the spark becomes clothed by the well-known yellowish envelope capable of being blown aside, and the blue negative light begins to appear. A moving mirror, as M. Lissajous has already observed,† shows an instantaneous spark at the commencement, in point of time, of the envelope and blue negative light, both which are drawn out, indicating a very appreciable duration. On making the electrodes the envelope is formed in perfection, especially with approach somewhat nearer, the spark diminishes, and

† See Du Moncel, "Récherches sur la non-homogénéité de l'étincelle d'induction," p. 107.