CHEMISTRY, PHARMACY, AND MATERIA MEDICA.

CHEMISTRY, PHARMACY, AND MATERIA MEDICA.

500 This cure girl was re-admitted to the hospital a few weeks after her for another affection, and the hymen was then found to be arabic, which ena...

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500 This cure

girl was re-admitted to the hospital a few weeks after her for another affection, and the hymen was then found to be

arabic, which enable them to work these wonders. Dr. Faraday’s

exposition of the matter was as follows:-The printed page to copied is laid upon blotting paper, and the reverse side is sponged over with very dilute nitric acid, so as to render the paper damp throughout; superfluous moisture is then removed by blotting paper, and the sheet is placed (the printed surface, to be copied, downward) upon a perfectly clean and polished zinc plate; a fold or two of bibulous paper is laid over it, and it is submitted to a careful, equable, and powerful pressure, by passing through rollers turned by means of levers. The effect

be

ruptured." ON THE ANTIPERIODIC PROPERTIES OF BEBEERINE.

Dr. DOUGLAS MACLAGEN has published a paper on the medicinal properties of bebeerine, a vegetable alkali discovered by Dr. Rodie in the bebeera or greenheart tree of British Guiana. From numerous trials which have now been made of this substance, it to possess all the antiperiodic properties of sulphate of quinine, in intermittent fever, neuralgia, and other diseases. A sulphate of the alkali is manufactured by Mr. Macfarlane, manufacturing chemist, of Edinburgh, of great purity. Its price is 6s. an ounce, whereas that of quinine is 12s. 6d. Forty cases are given illustrative of its beneficial effects, from which it would the sulphate of bebeerine, in the same doses as that of appear that quinine, while it is equally useful as an antiperiodic, has been observed on some occasions not to produce the unpleasant congestive effects occasioned by that drug. This substance undoubtedly demands, from its cheapness and valuable properties, the notice of the profession, especially of those who practise where intermittents are common.—Edin. Med. and Surg. Journal. seems

of this is to moisten the zinc plate with the dilute acid, where the unprinted part of the paper comes into contact with it, and a slight corrosion or biting in is effected; at the same time the ink of the printed letters parts with a slight film, which is left on the zinc plate. This is technically termed setting off, and from this the process is designated anastatic printing. The success of the subsequent process depends upon two principles which, Dr. Faraday says, have received some scientific elucidation very recently ._namely, the nzutual repulsion of oil and water, and the cohesion of the particles of fluids among themselves. This attraction of the particles of oil for oil, and water for water, is a far more energetic force than has been hitherto imagined. Upon ON THE FREQUENT SPONTANEOUS CURE OF PULMONARY CONthe repulsion of dissimilar, and the mutual attraction of similar SUMPTION, AND THE INDICATIONSFURNISHED BY PATHOLOGY particles, anastatic printing depends. In illustration of the FOR ITS RATIONAL TREATMENT. operation of these forces, together with the repulsion of water by Dr. J. HUGHES BENNETT states, that of seventy-three bodies he polished metallic surfaces, a few simple experiments sufficed. has examined since last November, he found puckerings or con- Thus, water will run over a clean metallic plate, as tin or zinc, cretions in the lungs in twenty-eight. They were combined without wetting it. If a thin layer of water is laid over a surwith induration alone in twelve, with cretaceous or calcareous face,-such as a china plate, for instance,-and a particle of oil is concretions in sixteen. They occurred in the right lung seven placed on it, the water will be repelled on all sides of the oil. In times, in the left lung twice, and in both lungs nineteen times. like manner, water will run off from an oiled surface without He thinks that these observations, conjoined with those of Roger wetting it. and Boudet, serve to establish that the spontaneous cure of pulOn the zinc plate, treated as described above, there are two monary tubercle occurs in the proportion of from one-third to kinds of surfaces,-one whereon the letters have left a film of one-half of all the individuals who die after the age of forty. oil-printer’s ink being a mixture of oil and lamp-black-the Dr. Bennett observes, that as empirical means for other wetted with the dilute nitric acid. The next step is to rub a cure have notoriously failed, perhaps a study of the method in printer’s ink over the surface by means of a rag, and the operation which nature operates may be more successful. There seems no requires no nicety or care, the ink will adhere only to the imreason why cavities in the lungs should not heal with the same pression of the letters, not to the wetted part corresponding to the frequency as ulcerations or abscesses in other internal organs, white unprinted part of the paper. Then, again, the whole is if the further deposition of tubercle could be arrested. This is rubbed over with another rag wetted with water, holdingin only to be accomplished by overcoming the pathological con- solution gum arabic, and what the inventors call phosphatic acid. ditions on which the deposition of tubercle depends. These are- This phosphatic acid is prepared by placing a stick of phosfirst, a morbid state of the blood, the result of imperfect nutri- phorus in water in such a manner as to allow a portion of the tion ; secondly, local inflammation, by means of which an un- stick to remain above the surface of the water exposed to a slow healthy exudation is poured out that assumes the form of tuber- process of oxidisement in the air. The principle upon which cular or scrofulous matter. The indications for treatment are- the action of this solution depends is by no means obvious. The 1st, To overcome the dyspepsia and acidity in the alimentary effect is, that the surface around and between the letters on the canal; 2nd, To furnish the material necessary for the formation zinc plate becomes so wetted, that no ink will adhere to it, whatof a healthy chyme; and 3rd, To combat the local inflammation. ever may be the force with which it is applied. The addition of The dyspepsia and vomiting are often to be alleviated by naphtha. the smallest portion of gum arabic to water will cause it to wet He attributes the good effects of this remedy to its power of allay- surfaces of metal or other substances, over which it would othering the irritability of the stomach, and thus enabling the patient wise pass without leaving the least trace of moisture. to take nourishment. In following the second indication, he The application of the solution of gum and phosphatic acid now, after four years’ employment of it in private, as well as in having been made, nothing more is necessary than to apply dispensary and hospital practice, strongly recommends cod-liver printer’s ink to the zinc plate by means of a roller, as in lithooil as a most valuable remedy.—Edin. Med. and Surg. Journal. graphy, and it will now print hundreds, nay, thousands of impressions so beautifully as fully to equal the original, and being so exact a fac-simile as to require the most nice observation by AND the experienced eye of a printer to distinguish from letter-press CHEMISTRY, or copper-plate printing. MATERIA MEDICA. The same rollers and machinery employed to take the impression upon the zinc plate suffice for ANASTATIC PRINTING. printing the number of copies required. It is, however, found, A RECENTLY invented process, termed anastatic printing, was that after a number of impressions have been taken, the letters made the subject of a lecture at the Royal Institution in Albe- begin to spread, the edges becoming blurred. In this case, all marlestreet, on Friday, April 25, by Dr. Faraday. It is in that is required to be done is to clean off all the ink from the many respects worthy of the attention of our chemical readers. plate by a rag, and it is found, that so permanent is the property When this discovery was first announced, and it was said that a imparted to the surface of the plate, that merely washing it over with the gum and phosphatic acid solution, the letters will again means had been devised to copy from a printed page of any size, take up the ink from the rollers, and print again, with the edges a line engraving, or any other print,-say, for instance, a page of the Times newspaper, upon a surface which would imme- as sharp and clearly defined as ever. Thus the renewal may be diately furnish an impression-a perfect fac-simile of the former, repeated, and the printing proceeded with, ad infinitum. But there is still another highly ingenious device belonging the process requiring only a few minutes to complete; and that from the same surface many thousands of similar impressions to this process. When it is desired to copy print or engraving might be taken, it was said that the thing was absurd ! impos- which is very old, and which, therefore, will not, by the above sible ! After the inventor had shown the possibility of these method, set off, the copy is placed in a weak solution of caustic extraordinary achievements, by producing copies of engravings potash, which pervades the paper, and softens the surface of the and printed sheets, the method by which it was accomplished was ink forming the letters; it is then dipped into a solution of tarconsidered to be a profound mystery; even electricity requires a taric acid, which, combining with the potash in the texture of and the the paper, forms bitartrate of potash, an insoluble salt, which considerable time; but this process may be copy exhibited, in a few minutes. Scarcely less marvellous than remains in minute crystals in and on the white part of the paper, its results is the simplicity of the principles involved in the and the ink roller may now be passed over it, when it will operation, and the small number of materials it requires. Every- impart a thin surface of fresh ink to the printed letters without thing depends upon the ingenuity of the inventors, who have soiling the intermediate white of the paper, and the copy may studied and discovered new properties in water, oil, and gum now be treated like a recently printed sheet.

accomplishing

PHARMACY,

completed,