laws of reflection and refraction; the formation of images by lenses.

"4th. Heat: the thermometer; latent and specific heat; phenomena of freezing; ebullition; evaporation.

66

5th. Electricity: conductors; insulators; electrical machine; Leyden jar; lightning, protection by conductors. "6th. Chemistry of the non-metallic elements; the atmosphere; combustion; respiration; water; general nature of acids; bases and salts.

"7th. To these should be added, though it cannot be called physical science, a certain amount of Physiology, giving a general view of the functions of the heart, the brain, the lungs, and the stomach in animals, contrasted and compared with the functions of the roct, stem, and leaves of plants.

Answer to Question 2:—“The object to be kept in view is not to make accomplished students in physical science, or even to induce the pupils to follow it, but to ensure a knowledge, exact as far as it goes, of the elementary principles of some of the most important branches

of science.

"The instruction will be best imparted by lectures, with experimental illustrations and diagrams, with frequent oral and written examinations during the course. There should also be periodical examinations of the pupils, and prizes for proficiency; such periodical examinations to be conducted, and the prizes to be awarded, by examiners who have not been engaged in instructing the pupils examined.

Answer to Question 3:- Upon this point I speak with less confidence; but I think it might be required that in each school a competent teacher of science should constitute one of the staff of masters, who should give instruction to the pupils who have risen above a certain position in the school."

We believe that we shall better assist in promoting the object Dr. Wood has in view by quoting the above eminent authorities, than by any further reference to the Doctor's pamphlet; but we must quote his reasons for preferring to teach young boys.

"That elder boys do not take to chemistry with the same readiness and earnestness as younger ones is amply shown by the students sent up to the universities and to the several London medical schools. These young men, as a rule, know absolutely nothing of chemistry when they come up; and of those who know nothing of it at the commencement of their studies, but few can be induced to take any reasonable pains to acquire even a superficial knowledge of it. This state of things is slightly improving under the increased facilities afforded of late years, for the early acquirement of familiarity with future studies. It is, however, only necessary for a good chemist to read the prescriptions written by large numbers of the medical profession to discover a lamentable want of accurate chemical knowledge. In further illustration of this point may be mentioned the complaints of some of the examiners of the London Medical Boards, that they are obliged to keep the standard of the chemical part of their examinations lower than it should be, because the men come so badly prepared."

Journal für Practische Chemie. Nos. 8 and 9, 1865. NUMBER 8 of this journal contains three original papers by Dr. Max Vogel. The first is "On a New Method of Forming Trichlorphenylic Acid." The author passes a rapid stream of chlorine through a solution of sulphophenylate of potash, by which trichlorphenylic acid, acid sulphate of potash, and free hydrochloric are produced.

The next paper is on Ethylenviolet." The author first describes some attempts to produce Hofmann's Dahliablue by a cheaper reagent than iodide of ethyl. He heated an alcoholic solution of rosaniline with the chloride and nono- and bisulphides of ethyl, and also with mercaptan,

but found that no one of these bodies produced any change in the rosaniline. He then tried the effect of substituting the corresponding compounds of e'hylene for the iodide and bromide of ethyl. When aniline red is heated with bromide or iodide of ethylene it requires close observation to see that any change takes place, for rosaniline and its salts are not soluble in the ethylene compounds. But when the solid mass is separated from the supernatant liquor, and dissolved in alcohol, a beautiful violet solution is obtained, which behaves exactly like that prepared by means of iodide of ethyl. The change takes place quicker when an alcoholic solution of rosaniline or fuchsine is used instead of the solid colouring matter. The author names the new colour Ethylene Violet, and shows that its composition is analogous to that of Hofmann's ethyl violet. Dichloride of ethylene has no action on rosaniline, but the author shows how the violet blue may be obtained by varying the process, and first heating aniline with the dichloride of ethylene, and treating the resulting product with arsenic acid. Dr. Vogel has also studied the behaviour of other chlorine compounds of alcohol radicals towards rosaniline, and has obtained a beautiful colour by the action of chloride of benzoyl on an alcoholic solution of aniline red.

The author has another paper " On the Action of Nitrous Acid on Aniline and the Aniline Colours." We now give the author's summary, and may return to the paper at a future time. I. The final product of the action of nitrous acid on aniline and the aniline colours, whether in aqueous or alcoholic solution, is in every instance a yellow colouring matter; hence nitrous acid would appear to be an excellent test for aniline colours. 2. The yellow matter obtained from aniline is different to that resulting from solutions of aniline colours. That from aniline colours is reddened by alkalies and again made yellow by acids; that, on the contrary, resulting from aniline is reddened by acids and the yellow is restored by alkalies. 3. The final product of the reaction of nitrous acid gas on solutions of aniline colours is the same for all the colours-namely, a yellow body, to which he gives the name "Cinalin."* cinalin from rosaniline has the composition C0H19N2O12 No other papers in this number call for notice. Number contains but two articles which we have not already noticed in other journals. One of these is by Dr. Rube, "On a Volumetric Method of Estimating Chromates." The method is founded on the fact that one equivalent of chromic acid will convert three equivalents of yellow into red prussiate. The chromate is dissolved in water, hydrochloric acid is added to set the chromic acid free, and the solution of yellow prussiate is added until a slight excess of the last is apparent, which is ascertained by placing a drop in contact with a drop of acid solution of perchloride of iron on a white plate.

The

The other article is by Osann, "On Antozone," in which he shows that the white vapour produced in the slow combustion of phosphorus in moist air which Meissner (see CHEMICAL NEWS, vol. x., p. 2, et seq.) took for anto zone, is really what Schönbein has already stated-viz., nitrite of ammonia, or atmospheric air metamorphosed into a salt.

North London Industrial Exhibition.-This, the most important of the many local exhibitions which have recently been held in London, was opened on Wednesday last. We must content ourselves now with remarking that it contains an admirable display of philosophical apparatus by many of the first makers in London. We intend to notice the contents in detail on future occasions, but must recommend our readers to pay the exhibition a visit.

The author writes Zinalin, a name he founds upon the resemlate Zinalin by Cinalin. blance of the new body to Zinnober = Cinnabar. We therefore trans

Death of Signor Piria.—At the last meeting of the Academy of Sciences, M. Dumas announced the decease of Piria, so well known by his researches on salicine. Chemistry at Oxford.-Some weeks ago the University of Oxford advertised for a Waynfleete Professor of Chemistry. People not in the secret supposed that Oxford had become so convinced of the importance of chemistry that they intended to endow a second professorship. Dr. Daubeny, however, has made known-and he certainly deserves thanks for the communication--that the new professorship is of more value than the Aldrichian, which Sir B. Brodie now holds, and consequently this gentleman is expected to apply for the new appointment. In the event of his election to it, Dr. Daubeny states that the old professorship will be suppressed, and its endowments applied to other purposes. Of what these other purposes may be the Doctor gives no hint, and it is impossible to conjecture. But we may suggest that the funds would be well applied in the endowment of chemical scholarships or fellowships for students who exhibit special aptitude for original research. There are very few opportunities in England for rewarding a student engaged in the pursuit of science without regard to any practical application of it; and it would look well if the University, which has for ages expended its enormous revenues in the encouragement of learning, which, however much it may adorn, has done very little to materially benefit the human race, were at last to do something to promote a science which has done almost more than any other, and must now be regarded as the most important of all the natural sciences. No one, we believe, is more conscious of the importance of our science than its accomplished Oxford Professor, and chemists will look to him to exert his influence on its

behalf.

Gale's Non-Explosive Gunpowder.-Mr. Gale is repeating his experiments in various places with undoubted success, and the subject is attracting much attention. The secret is now made known by the publication of the patent, and we learn that the incombustibility is produced by mixing one part of gunpowder with three or four parts of finely powdered glass. By the addition of this powder every grain of gunpowder is isolated, and thus only those grains are ignited which come immediately in contact with the source of heat. Mr. Gale is not the first who has experimented in this direction. A French and a Russian chemist have both made experiments on the subject. M. Piobert, in 1835, tried a variety of substances, and among them sand. He tried, also, the separate constituents of gunpowder, and of the three gave preference to nitre, which he found to deprive gunpowder of its dangerously explosive character. M. Fadéieff, the Russian, preferred a mixture of wood charcoal and graphite, which he found to be unaffected by moisture. Mr. Hearder has lately found almost any dry compact powder will answer the purpose, and states that pipe-clay, gypsum, or chalk do very well. Our readers know that Mr. Gale only proposes that stored gunpowder, and powder for transport, should be treated with his process. When this powder is required for use the fine glass is separated by means of a sieve, and the question which is engaging attention is whether or not the powder is damaged by being submitted to this treatment. One writer suggests that glass powder is liable to become alkaline, and therefore hygroscopic. Mr. Hearder objects that it may not be possible to separate the glass completely, and therefore the explosive force of the powder must be more or less diminished. The Realer mentions some experiments which "seem to show that the addition of the protective powder to ordinary powder has the effect of rendering the explosion more gradual"-an effect which would be valuable if the protective powder were combustible. We have not yet seen any notice of the effect of the glass on the glazing of the powder, any interference with which would seriously affect the quality of the powder, particularly of the finer kinds. On the

whole, we must conclude that the practical value of Mr. Gale's invention has yet to be demonstrated. It is indeed very desirable to have a means of rendering gunpowder combustible or non-combustible at will; but to be really available the results must be accomplished with less trouble and risk than is the case with Mr. Gale's process. Haarlem and Utrecht Prize Questions.-The Dutch Society of Sciences at Haarlem have this year proposed the following questions, the time for which will expire on the 1st of January, 1867-1. The exact determination of the heat produced by the combustion of the glycerides. 2. A better method than fractional distillation for separating mixed homologous bodies. 3. Researches on the diminution of temperature in the successive strata of the atmosphere, found to be not the same in different latitudes. 4. An illustrated memoir containing exact microscopical researches upon the formation and the development of the egg in the ovary of fishes and birds. 5. A complete monograph on the lichens of Pays-Bas. 6. The precise determination of the density and the dilatation of a mixture of water and methylic alcohol. 7. The exact determination, at different temperatures, of the density of at least five bodies soluble in water. 8. To discover by means of microscopic researches, the cause of the regular non-development of a portion of the seeds of many plants. 9. The elimination of the error in volumetric researches caused by the condensation of the gases on the surfaces of the vessels employed. 10. The determination of the temperature of deep still water, such as lakes, at different depths from the surface. 11. A minute description, from new experiments, of the fecundation in as large a number of plants as possible belonging to the family of grasses. The Haarlem Society of Sciences have also decided to publish a journal in French containing the memoirs that have been read before the Society. The frequency of publication of the journal will depend on the number of memoirs presented. The editorship is entrusted to the perpetual secretary, Mr. E. H. Von Baumhauer, assisted by several Dutch savans.

To Keep Eggs.-M. Bournouf recommends in Le Belier, a French journal of agriculture, the following method of preserving eggs:-Dissolve in two-thirds of warm olive oil one-third of bee's-wax, and cover each egg completely with a thin layer of this pomade with the end of the finger. The egg-shell by degrees absorbs the oil, and each of its pores becomes filled with the wax, which hermetically seals them. M. Bournouf affirms that he has eaten eggs kept two years in this manner, in a place not exposed to too great extremes of temperature. He thinks also that the germ may in this manner be preserved for a considerable time.

Vol. XI. of the CHEMICAL NEWs, containing a copious Index, is now ready, price 118. cd., by post, 118. 6d., handsomely bound in cloth, price 18. 6d. Subscribers may have their copies bound for 2s. 6d. if gold-lettered. The cases for binding may be obtained at our Office, sent to our Office, or, if accompanied by a cloth case, for 18. Vols. I. and II. are out of print. All the others are kept in stock. Vol. XII. commenced on July 7, 1865, and will be complete in 26 numbers.

NEWS

impossible," and suggests that the employment of anhydrous sulphuric acid may accomplish the object by dissolving out the body of the formula CH2.

3. And so recently as 1862, Schorlemmer,|| in his first paper "On the Hydrides of the Alcohol Radicals existing in the Products of the Destructive Distillation of Cannel Coal," remarks that "it was, however, found impossible to obtain a product of constant boiling point by repeated fractional distillations," and he also had recourse to the acid treatment above referred to.

The want of a more efficient process for effecting such separations has long been recognised. There are numerous natural and artificial products of the highest scientific interest-such as petroleums, essential oils, tars, and other mixtures of oils obtained by the distillation, under varied circumstances, of bituminous, vegetable, and animal substances-of which it may at least be said that we have but very imperfect knowledge-I might almost say no knowledge, except such as could be derived from the study of very impure materials-still mixtures of different bodies-with which, instead of the pure substances sought for, chemists have felt compelled to content themselves, as the best results which they were able to obtain by the means at their command.

In repeated instances, apparently after persevering and protracted efforts, investigators have been forced to assert either the impossibility or their inability to obtain from such mixtures bodies of constant boiling point-a property which is generally received as a test of purity for liquid bodies.

I may here specify a few recent instances of this kind. 1. Warren de la Rue and Hugo Müller,+ in their paper entitled "Chemical Examination of Burmese Naphtha or Rangoon Tar," after detailing the preliminary treatment by distillation in a current of steam, add that "A further separation of the various products was effected by repeated fractional distillations, but no absolutely constant boiling points could be obtained, notwithstanding the great number of distillations and the large quantity of material at command. It is true that considerable portions of distillates could be collected between certain ranges of temperature, tending to indicate a constant boiling point; nevertheless, it soon became evident that distillation alone could not effect the separations of the various constituents, and that recourse must be had to other processes." The other processes resorted to were treatment with sulphuric and nitric acids, either separately or mixed; but still with very imperfect results. This acid treatment, which was first proposed by De la Rue, and subsequently employed by C. Greville Williams, Schorlemmer, and others, will be further noticed below.

Such is the general character of the results obtained in the attempts which have been made to separate the constituents of such mixtures by fractional distillation. The treatment with strong acids, &c., as an auxiliary to the common method of fractional distillation, which is claimed to have given good results in some cases, is open to serious objections in its application to mixtures of unknown substances, as must be readily apparent. The further consideration of this subject is reserved for another occasion, when I shall submit the results which I have obtained by my process in the study of mixtures almost identical with some of those in the investigation of which the acid process has been employed. I shall then be able to show that the results obtained by that process are, to a considerable extent, inaccurate and by no means exhaustive, and that it is still of the highest importance to have a process which shall be generally applicable in all such cases, without resort to any harsh and uncertain treatment.

With regard to the value of constancy of boiling point above referred to, as a test of purity of a liquid substance, I may here say that, without scarcely lessening the importance of obtaining constancy of boiling point, before resorting to harsher treatment, in the study of mixtures of unknown substances, I think I shall be able to show on another occasion that this property is not necessarily indicative of so high a degree of purity as has generally been supposed, and that a body may have a constant boiling point, and yet contain enough of a foreign substance to appreciably--and in delicate cases seriously-affect the determination of its constitution and of some of its other properties. But in no such case have I yet found that the removal of the impurity by chemical means has essentially changed the boiling point-i.e., never to the extent of 1° C. of temperature. I propose at a future time to study this question synthetically, operating with pure liquid substances, with the view to determine in a few cases how much of a foreign substance may be present-which would probably be variable in different cases-without sensibly affecting the boiling point. A solution of this question would, I

Journal of the Chemical Society, xv. 419.

Annalen der Chemie und Pharmacie, cxv. 20, asserts the "Unmög

* Annales de Chimie et de Physique, 3 Série, xlii. 132.

+ Proceedings of the Royal Society, viii. 221.

Philosophical Transactions, 1857, 447.

§ Quarterly Journal of the Chemical Society, 1851, 3, 43. VOL. XII. No. 299.—August 25, 1865.

** Annalen der Chemie und Pharmacie, cxiii. 169, says as follows:"Mit den 5° zu 5° aufgesammelten Destillaten wurde die fractionirte Destillation wieder von Neuem vorgenommen, aber nachdem diese Operation sieben Wochen mit etwas 50 Pfund Steinöl fortgesetzt worden war, erhielt ich doch kein Product von irgend constantem Siedepunkt. Nach diesen Versuchen halte ich es für Unmöglich, das Steinol durch fractionirte Destillationen allein in Producto mit constantem Siedepunkt, zu scheiden.”