formed of sufficiently strong and thick glass, to prevent the chance of breakage. I may remark, that many of those mounted with ivory soon become useless, in consequence of the giving way of the medium which is employed to fix them. Trusting that these observations may be the means of counteracting the various complaints made against these simple instruments, which have received the approbation of the profession, I have the honour to remain, your obedient Servant, 5, George Street, Hanover Square, Nov. 1842. W. ACTON. ON THE DETERMINATION OF AZOTE IN ORGANIC SUBSTANCES, BY THE PROCESS OF MESSRS. VARRENTRAPP AND WILL. BY M. REISET. M. REISET has submitted the new process of analysis of MM. Varrentrapp and Will to a careful examination, with the view of ascertaining how far it may be relied upon as a means of correctly estimating the quantity of azote contained in organic bodies. He says, the fundamental conditions. essential to place the new method of analysis beyond all objection, are, first, that the whole of the azote contained in the azotised substance shall be transformed into ammonia; and, secondly, that the azote of the air contained in the combustion tube, shall not, in any case, contribute to the formation of ammonia. The experiments of Berzelius, and more recently those of Varrentrapp and Will, have shown that the first of these conditions is completely fulfilled. All azotized substances, with the exception of those containing azote in the state of nitric acid, transform the whole of their azote into ammonia, under the influence of the alkaline mixture, at an elevated temperature. The combinations of cyanogen even, furnish ammonia as easily as a mixture of sal ammoniac and lime. With regard to the possibility of the formation of a certain quantity of ammonia at the expense of the atmospheric air contained in the tube, MM. Varrentrapp and Will have made the following experiment to meet this objection. A mixture of azote and hydrogen, such as arises from the decomposition of ammonia by copper, was passed, at a red heat, 1st, over a mixture of calcined cream of tartar and lime; 2dly, over a mixture of recently prepared lamp-black and calcareous soda; and 3dly, over the simple mixture of lime and soda. In none of these cases were they able to. detect the least quantity of ammonia formed. This experiment was considered sufficient, by these authors, to establish the accuracy of the indications afforded by their process, and any excess of azote which may appear in the result of the analysis, they ascribe to impurities in the substance analyzed, or in the chloride of platinum. : These conclusions appear to me not to be sufficiently established, for although a mixture of azote and hydrogen produced no ammonia under the circumstances of MM. Varrentrapp and Will's operation does it therefore follow that a non-azotized substance, or one very rich in carbon, when burnt with the alkaline mixture in contact with atmospheric air, never yields ammonia? This question was rendered the more interesting, in consequence of the announcement, some time ago, by Faraday, that non-azotized substances, such as sugar, acetate of potash, oxalate of lime, tartrate of lead, &c., when calcined See Pharmaceutical Journal, Vol. i., p. 494, with hydrate of potash, of soda or baryta, always afford a sensible quantity of ammonia. It is evident, on reading the paper of this able Chemist, that the re-agents employed by him were perfectly pure, having been prepared by himself with great care. It remained to be determined with accuracy whether the facts observed by Mr. Faraday might have some influence on the results of the process of analysis of MM. Varrentrapp and Will. The following experiments appear to me to leave no doubt on this point : The sugar employed by the authors of the process to prevent the too rapid absorption of the ammonia by the hydrochloric acid, during the combustion of substances very rich in azote, also sugar burnt in the ordinary apparatus with the alkaline mixture, have always afforded me quantities of ammoniacal chloride of platinum, which, as will be seen, are by no means unimportant. The ammonia obtained under these circumstances, can only be ascribed to the azote contained in the tube, and not to the re-agents employed. The mixture which I used was prepared with all the care possible, by calcining at a red heat in an earthen crucible, two parts of slaked lime with an aqueous solution of one part of caustic soda recently prepared. The mass was quickly powdered, then slightly heated to drive off any moisture it might have attracted, and introduced while still hot into a stoppered bottle. After first proving by experiment, that neither the alkaline mixture nor the chloride of platinum used in my experiments, contained any azote, I proceeded to the combustion of sugar. 1st. One gramme (15.444 grains) of sugar, perfectly white, was burnt in an ordinary tube with the alkaline mixture, which, on the addition of the chloride of platinum to the hydrochloric acid, afforded very brilliant, yellow, insoluble crystals of chloride of platinum and ammonium, and which, after calcination, gave .089 gramme of metallic platinum, corresponding to .0127 gramme of azote. 2d. Two grammes of the same sugar, gave under similar circumstances, .10725 gramme of metallic platinum, corresponding to .0153 gramme of azote. 3d. One and a half gramme of sugar-candy, in fine crystals, gave .104 gramme of metallic platinum, corresponding to .0149 gramme of azote. I also effected the combustion of stearine, and obtained ammonia from it. The new process for the determination of azote has succeeded perfectly, in the hands of MM. Varrentrapp and Will, in a great number of cases; several other Chemists have also reported favourably of it: these are facts which I am by no means disposed to doubt; but it is important that it should be distinctly understood, that this process may lead to serious errors in operating on non-azotized substances, or even on azotized substances which are very rich in carbon, and the combustion of which is difficultly effected with the alkaline mixture. Moreover, there exists another source of error in the employment of this process, which deserves to be mentioned. I allude to the reduction of a small quantity of the bichloride of platinum into protochloride under the influence of the mixture of alcohol and ether. Faraday, in his paper on some circumstances attending the formation of ammonia, has shown that iron, zinc, and those metals, generally, which are easily oxidized, when fused in contact with potash, give rise to the formation of ammonia, even in an atmosphere of hydrogen. I have ascertained, in fact, that at a temperature which need not be higher than 265° Fahr., iron filings and a concentrated solution of potash afford an abundant evolution of hydrogen, and at the same time the smell of ammonia becomes very sensible, even in operating with a grain of potash. But this formation of ammonia does not take place, if the operation be conducted in an atmosphere of hydrogen prepared with sulphuric acid, free from nitrous gas.-Annales de Chimie et de Physique. CHINOVA-BITTER. BY DR. F. L. WINCKLER. IN preparing a large quantity of Chinova-bitter, I had occasion to study accurately the chemical properties of this bitter matter. According to the results of these experiments, the Chinova-bitter is a well-characterized acid, which not only forms with most metallic oxides amorphous compounds soluble in water, but forms also with ammonia, soda, and potash, perfectly neutral but uncrystallizable salts easily soluble in water. The solution of the ammonia salt loses the ammonia completely, either by being evaporated under moderate heat, and even by spontaneous evaporation in the air, and, on being evaporated to a state of dryness, leaves behind the Chinova-bitter as a very easily friable, enamel-like, snow-white, amorphous mass. The potash salt is to be obtained by the evaporation of the solution in a perfectly undecomposed state, and forms, when dry, a mass easily friable, and rather shiny; it dissolves very copiously in water; the aqueous solution is decomposed by carbonic acid, with the deposition of unchanged Chinova-bitter. All salts of Chinova-bitter possess a very bitter taste, fuse, when heated with a spirit lamp, and are decomposed, developing copious vapours, of a peculiar odour and white colour. If a flame be brought in contact with the melting mass, the vapours easily ignite, and the mass is burnt completely, presenting a clear, full, red, strongly sooty flame, the metals or oxides remaining behind. The combination of the oxide of silver with Chinovabitter, which can be easily obtained by the decomposition of the neutral ammonia salt, by nitrate of silver, in the form of a white gelatinous precipitate, will dry up (even if the access of air be carefully prevented) into a blackish-grey, or nearly black, amorphous, easily friable mass. 0.2 grammes of the dry silver compound, after being burnt, left behind, according to these experiments (the results of which correspond very well with each other), at an average 0.042 grammes of silver=.0043659 grammes of oxide of silver. The per-centage composition, therefore, of the compound is, 78.1705 Chinova-bitter. 100. Another result had been previously obtained by the analysis of the compound of silver, which I had procured by means of nitrate of silver from a basic fluid, prepared by boiling a mixture of lime, Chinova-bitter, and water. 0.315 grammes of this compound left behind, after being burnt, 0.145 grammes of silver 0.1507 grammes of oxide of silver, which corresponds with the per centage composition of 52.1517 Chinova-bitter. 100. This compound is therefore a basic one. The above may suffice as a contribution to the more accurate chemical knowledge of the Chinova-bitter. It remains to be elucidated in what relation Chinova-bitter stands to Chinova acid (Pelletier and Caventou). I have, in operating on large quantities of China nova, endeavoured in vain to find this acid, which, according to the opinion of the above chemists, does not precipitate salts of the oxides of iron, copper, or silver. In my former communications on the composition of this bark, I have stated them on the authority of Pelletier and Caventou, my attention having been particularly directed towards the Chinova-bitter. On this account I reserve to myself a repetition of the qualitative and quantitative analysis of the China nova; but according to what I have hitherto observed about the chemical relation of the Chinova-bitter, I might now rather designate it by the name of Chinova-bitter acid. A confirmation of the different statements on the composition of Chinova-bitter of Messrs. Buchner and Petersen may be soon looked for, as Professor Wöhler, of Göttingen, is causing the elementary analysis to be repeated, and there can be no doubt that the results will be duly published.--(Pharm. Central-Blatt, Sept. 17, 1842). [The red bark, known in France as Quinquina nova, and in Germany as China nova, is the produce of Cinchona oblongifolia. It is very different from the red bark of English commerce, though the London college has confounded them together, and ascribed our red bark to the tree which yields Quinquina nova, and which is sometimes called Mutis's Red Cinchona of Santa Fé.ED. PHARM. JOUR.] ON HUICHUNCHILLY. THE plant which yields Huichunchilly is, according to Dr. Martius, the Ionidium Marcucci Hooker, called in the Mexican language, Kuitschundschulji, and already mentioned, described, and figured in Feuillées Jour. des Observ., t. iii., b., p. 41. Paris, 1725. The Jesuit Velasco, at Quito, mentioned the plant and its medicinal properties, first in a MS. history of Quito, which came subsequently into the hands of Carea, the vice-president of the republic Ecuador. The latter caused the notice relating to it to be published, which first induced Dr. Aracha, of Maracaybo, to make experiments with it, and subsequently (1834), M. Marcucci undertook a journey to the place where this plant grows. After many fruitless enquiries, he found ultimately, that the plant grows only on the foot of Chimborazo, and was best to be had at Riobamba, where he obtained a small supply. He sent specimens, with remarks thereon, to Bancroft, at Kingston, in Jamaica, which were published by the latter in the Physical Journal of Jamaica. Sir W. Hooker, in 1836, determined the nature of the plant, from specimens obtained by Marcucci, and gave it the above name. It is identical with the small-leaved Ionidium, which had been described by Humboldt, from Columbian specimens, by M. Hilaire from Brazilian specimens, of which there are also specimens at Glasgow, obtained from North Chili (there called Paytensillo), and according to Caranilles, it grows also in Montevideo. It appears, therefore, that the plant is rather extensively distributed, which would seem to contradict the assertion, that the Chimborazo plant alone produces any effect.-(Pharm. Central-Blalt, Sept. 17, 1842.) [The root of the Ionidium mycrophyllum, called Cuichuncully, has been recommended by Dr. Bancroft (Hooker's Companion to the Botanical Magazine vol. i., p. 278), in that most intractable disease called Elephantiasis tuberculata. It is probable, however, that its properties are similar to the false Brazilian Ipecacuanha (Ionidium Ipecacuanha), and that for both of these, the root of our own indigenous sweet violet (Viola odorata) might be substituted, as they all belong to the same natural family, Violacea. - .ED. PHARM. JOUR.] FLUID OF SPINA BIFIDA. LANDERER describes this fluid, obtained by puncture, as being of the specific gravity of 1.005; clear, without smell, very slightly alkaline, frothing, and depositing during boiling (accompanied by some slight developing of ammonia) some flakes. He found the following substances in it: albumen, chloride of sodium, chloride of calcium, chloride of magnesium, and traces of phosphate of soda and ammonia.--(Pharm, Central-Blatt, Sept. 24, 1842.) DETECTION OF THE PRESENCE OF POTATO STARCH IN THE POWDER OF RICE OR ARROW-ROOT, BY MEANS OF DILUTED HYDROCHLORIC ACID. BY M. SCHARLING. IF powdered rice or potato starch be mixed with concentrated hydrochloric acid, in the proportion of about one part of the former to one and a half or two parts of the acid, they form almost immediately a thick mucilage. The mucilage of potato-starch is nearly transparent; that of the rice, on the contrary, is opaque. They both emit the odour of formic acid. If a mixture of hydrochloric acid and water be used, a very different action is exercised on the two substances already named. The potatostarch forms, in a very short time, a mucilage so thick, that the mortar may be lifted up by means of the pestle used in making the mixture; while the powdered rice does not acquire a similar viscosity in less than twenty-five or thirty minutes. If the rice-powder contains from four to six per cent. of potato-starch, it is easy to detect the admixture by means of this re-agent. For this purpose, a mixture of equal parts of hydrochloric acid of commerce and water should be used. Arrow-root comports itself in the same manner as rice-powder, with the hydrochloric acid, while wheat-starch resembles potato-starch in this respect. M. Marezeau, as is known, has proposed hydrochloric acid as a means of detecting potato-starch in flour, by the strong smell of formic acid which it developes in contact with the acid; but as the same effect is produced, in this respect, with rice-powder and arrow-root as with potato-starch, the hydrochloric acid cannot be used in this way for detecting the admixture of these latter.-Annalen der Chemie und Pharmacie. REVIEWS. CHEMICAL MANIPULATION. BY MICHAEL FARADAY, D.C.L., F.R.S., M.R.I. Third Edition. John Murray, Albemarle Street. HAVING already reviewed this work (see vol. i, page 222) we shall condense our remarks on the third edition into a small compass. It would indeed be superfluous to analyze in an elaborate manner a work which all our readers ought to possess, and which should precede and accompany the study of the Pharmacopoeia. The correct performance of every operation in Pharmacy being dependent upon manipulation, the importance of learning the principles of this art in a scientific and methodical manner must be self-evident to all who are engaged in such occupations. Professor Faraday observes, "The person who could devise only, without knowing how to perform, would not be able to extend his knowledge far, or make it useful; and where the doubts or questions that arise in the mind are best answered by the result of an experiment, whatever enables the philosopher to perform the experiment in the simplest, quickest, and most correct manner, cannot but be esteemed by him of the utmost value. It is, indeed, to him like the external senses to the mind-a channel of information by which things before unperceived are made known, and like them it has its continual use." Although these observations are made chiefly with reference to experimental researches, they are applicable to all the ordinary manipulations of the dispensing Chemist. It not unfrequently |