talum oxide has taken up about 18 per cent of its weight, in a porcelain Gooch crucible, and washed with water. of columbium oxide, and the latter over twice its weight The crucible was supported in a triangle on a sand-bath,, of tantalum oxide. The intermediate mixtures would then and covered with a 300 cc. flask whose bottom had been consist of mechanical mixtures of each oxide saturated removed. A glass tube and thermometer were fitted into with the other. In these mixtures the variations in densities the neck of the flask through a rubber stopper. The air in of different mixtures of the same composition are greatest. the flask was displaced by a rapid stream of carbon dioxide Points on this part of the curve should lie on a straight entering through the neck of the flask and escaping through line if the interpretation of these results as suggested is the sand at the bottom. The temperature was raised to 240° and maintained for two hours, while carbon dioxide was passed in. At the end of this time all free sulphur had been removed from the Sb2S, precipitate, as was shown by the weight remaining constant after further treatment. The crucible was allowed to cool in the atmosphere of carbon dioxide, its weight taken, and Sb2S3 calculated into terms of Sb2O3. correct. Composition. Per cent TagО5. Specific gravity. Average. specific gravity. 4'552 4.650 4'746 4'929 5.200 5°474 5.850 6:434 5 4'555 4'549 '4'652 4.647 ΙΟ 4'744 4*748 20 4'929 4929 6.737 7·083 The filtrate from the precipitation with hydrogen sulphide contained columbium and tantalum in solution in hydrofluoric acid. It was evaporated to dryness, moistened with concentrated sulphuric acid, and heated until all hydrofluoric acid was expelled. Water was added, and the solution made alkaline with ammonia, filtered, the precipitate washed, ignited, and weighed. After heating over a blast-lamp for an hour the density was determined. In experiments 2 and 3 the hydrofluoric acid solutions containing tantalum and columbium were united in order to obtain enough material for a reliable determination of density. The results of the analysis are given below. The density method was also applied to the partial analysis of a Branchville columbite, and for comparison tantalum and columbium were separated and determined by the Marignac method. The specimen contained no FIG. 1. 1 Analyses of Minerals by Density Method. The analysis of a sample of stibiotantalite from the Brush collection was carried out using the indirect method for determining the relative proportion of tantalum and columbium oxides. The density of the sample was 6.80 and the weight 4 grms. The method used was as follows: -Two I grm. samples and a 2 grm. sample were each dissolved in about 20 cc. of hydrofluoric acid. Some white insoluble material remaining undissolved was filtered off, and its weight deducted from that of the sample taken. The resulting weight was taken as that of stibiotantalite used for analysis. The solution containing an excess of hydrofluoric acid was diluted to 300 cc. and hydrogen sulphide passed in until all antimony and bismuth were precipitated as sulphides. The precipitate was filtered, washed with witer, and treated several times with yellow ammonium su phide. The insoluble residue of bismuth sulphide was dissolved in nitric acid, precipitated with ammonium carbonate, filtered, washed, ignited, and weighed as Bi203. The solution of antimony sulphide in ammonium sulphide was precipitated with sulphuric acid (in the case of the 2 grm. sample one-tenth of the solution was used), filtered 訂 It will be seen that the results are approximately alike by the two methods, but we believe the results by the density method are more accurate and they are certainly much easier to obtain. The specific gravity of the columbic oxide from one Marignac separation was found to be 4.612, corresponding to 96 per cent of columbic oxide and 4 per cent tantalic oxide, showing that some tantalum went with the columbium. It is probable also that some columbium crystallised with the tantalum double fluoride, but the amount of tantalic oxide was too small for a density determination. The authors wish to express their thanks to Dr. W. E. Ford and Dr. T. B. Osborne for the tantalum and colum bium oxides used in this investigation.--American Journal of Science, xxx., No. 180. REPORT ON CHEMICAL CONSTITUTION AND THE ABSORPTION OF LIGHT.* By W. W. STRONG. (Continued from p. 48). The Theory of Chromophores. In considering absorption spectra it is often quite sufficient to speak qualitatively of the colour of different compounds. The introduction of certain groups into colourless compounds often results in a coloured compound. Any such group is a chromophore. Sometimes the chromophore may be weak, and it may require the addition of several chromophores to produce a coloured compound. Ultimately the colour is due to absorbers existing in the Among chromophore-probably the valency electrons. the better known chromophores are the groups :— >C=c<, =CO, >C-NH, —CH=N—, —N-N-, Benzene is colourless and exhibits absorption only in the ultra-violet, whereas fulvene is an orange-yellow. The carbonyl group, C=O, is also weak, and several of the groups must be present in a compound to produce * This Report is based upon an article by H. Ley, entitled " Ueber die Beziehung Zwischen Lichtabsorption und Chemischer Konstitution bei Organischen Verbindungen." See Jahrbuch der Radioaktivität und Elektronik, 1910, vi., 274. From the American Chemical Journal, xliv., No. 1. The combination of two phenyl groups causes absorption only in the ultra-violet. The introduction of the -CH-Nchromophore is sufficient to produce colour, as is shown in the yellow benzylideneaniline, C6H5CH-N-C6H5. The azo-chromophore, N = N-, produces the same effect, as shown in the orange azobenzene, C6H5 - N = N-C6H5. The chromophores The carrier of the colour in these cases is the C-N=O group. Many of the aliphatic nitroso compounds show polymerisation and are then often colourless. The polymerisation of R-N-O to (RNO)2 is probably accompanied by a rearrangement as follows: R-NON-R. This would explain why the polymer is colourless. The nitro-group, -N chromophore. The aliphatic nitro-compounds, CH3NO2, C2H5NO2, &c., are colourless. When combined with other chromophores, coloured compounds, such as nitrobenzene or nitronaphthalene, can be obtained. Stobbe (Der., 1905, xxxviii., 4082) has investigated the influence of the nitrogroup on the fulgides. In solution the p-nitrophenylfulgide has a deep red colour. The ortho and meta compounds are much less deeply coloured. Hantzsch (Ber., xxviii., 2744) and Raschig (Dammer's "Handb. der Anorg. Chemie ") have shown that the -N-O group acts as a chromophore in the sulphonate, ON(SO3K)2, which is violet in solution and orange in The thiocarbonyl group, C=S, is the solid state. a rather strong chromophore. Examples are the blue compounds, thioacetophenone, C6H5-CS-CH3, and thiobenzophenone, C6H5-CS-C6H5. For a fuller account of the colour properties of various compounds, the reader is referred to Ley's paper (Jahrb. d. Rad. u. Elek., 1909, vi., 274), from which the data here recorded have been largely taken. There has been a great deal of discussion whether quinone has the folmula I. or II. Cresol. Dihydroxybenzene. Hydroxybenzoic acid. 3359 3080 2986 When a chromophore is introduced into a compound the bands may be shifted towards the red or towards the violet. The former effect is bathochromous, the latter hypsochromous. The effect of joining chromophores is usually bathochromous. For example: Benzene Naphthalene Anthracene In triphenylmethane the limit of the visible portion of the spectrum is reached. It may be stated here that anthracene and phenanthene have entirely different ab sorption spectra, although the fluorescent spectra are very similar (Elston, Astrophysical Journ., 19073 xxv., 3). An auxochrome is a radical that causes the absorption to be more intense. An example is -CO-C-C—co—, which appears in the indigos CO C6H4 NHC=CC6H4, and also in the deeply coloured compounds. C6H4CC=CCO C6H4> The groups CH3, OCH3, C2H5, the halogens, &c., are bathochromes, while the groups NO2 and NH2 are hypsochromes. The infra-red absorption spectra to about 15 μ of a large number of organic compounds have been investigated by W. W. Coblentz ("Investigations of Infra-red Spectra," Carnegie Publication No. 35). Isomeric compounds are found to possess very different absorption, depending on the bonding of the atoms in the molecule. Stereomeric compounds, on the other hand, were found to possess the same absorption spectra. The replacing of hydrogen by an NH2 or CH3 group usually results in the appearance of new bands. In the spectrum of certain benzene derivatives, however, the benzene spectrum is usually present. The carbohydrates investigated had characteristic spectra with absorption bands at 0.83 to 0·86 μ; 1·67 to 1.72 μ; 3.25 to 343 μ; 6 75 to 6·86 μ; and 13.6 to 14 μ. The three isomeric xylenes have banded spectra in which the most important line in each group lies farthest toward the long wave-lengths in the order ortho, meta, and para. The author (Phys. Rev., Dec., 1909; Feb., 1910) has acid is hypsochromous, causing the uranyl bands to shift shown that the effect of the NO3 group and of free nitric of zinc, aluminium, or calcium chlorides on the uranyl towards the violet. The effect of free hydrochloric acid or chloride bands is bathochromous. Recently the author has found that the NO3 group is hypsochromous with respect to the neodymium and erbium bands. (To be continued). Royal Institution.-On Thursday next, February 9, at 3 o'clock, Dr. P. Chalmers Mitchell begins a Course of three lectures at the Royal Institution on "Problems of Animals in Captivity"; and on Saturday, February 11, Dr. Thomas G. Jackson, R.A., delivers the first of three lectures on "Architecture-the Byzantine and Romanesque Period." The Friday Evening Discourse on February 10 will be delivered by Sir Sidney Colvin, on "Robert Louis Stevenson"; on February 17, by Prof. Henry E. Armstrong, on "The Stimulation of Digestive Activity"; and on February 24, by Prof. Jean Perrin, on "Mouvement Brownien et Realité Moleculaire" (in French). From the red blood cells of an infected animal, which have been agglutinated in the cold by the plasma of the same animal, an active substance can be extracted with normal saline solution at 37° C. This substance agglutinates not only the red cells of the same animal and other members of the same species, but also those of many Sir ALEXANDER GEIKIE, K.C.B., President, in the Chair. animals of different species. Observations of this kind PAPERS were read as follows: "Action of B. lactis aerogenes on Glucose and Mannitol." (Part II.). By G. S. WALPOLE. The "crude glycol" obtained by the action of B. lactis aerogenes on glucose contains two optically inactive 2:3 butane diols, whose diphenylurethanes melt at 199.5° and 157 respectively. The former constitutes well over 90 per cent of the material. If fructose be substituted for glucose in one of the flasks, the yield of "crude butylene glycol" and acetylmethyl carbinol is of the same order as when glucose is employed. Acetylmethyl carbinol is formed abundantly when the bacillus is cultivated in a solution of butylene glycol in 1 per cent peptone in a current of oxygen. "Pharmacological Action of Gonioma Kamassi (South African Boxwood)." By Dr. W. E. DIXON. South African boxwood, Gonioma Kamassi, has been employed occasionally in Lancashire as a substitute for common boxwood in the manufacture of shuttles; it is stated that symptoms of poisoning have occurred in a small proportion of the men engaged in sawing this wood or finishing the chiselled shuttles. From the wood an alkaloid can be obtained to about 0'07 per cent. This has a very characteristic physiological action which places it in the curare group of drugs. The members of this group may be regarded as possessing three actions in common. (1) Paralysis of certain nerve cells; (2) increase of spinal and medullary reflexes; (3) paralysis of motor nerve endings. Boxwood exerts all these effects. It paralyses the nerve cells in the brain and medulla as well as those on the course of the vagus and sympathetic nerves, and therefore after its exhibition to animals the stimulant action of nicotine cannot be obtained. In small doses the reflexes are increased, and if an injection be made into a vein going to the spinal cord of an animal, strychnine-like convulsions are produced. Boxwood causes death by paralysing the respiration; this is central in origin, but it occurs at a time when the phrenics and intercostals are depressed though not paralysed. Boxwood has no direct action on the heart or on other form of muscle. Reasons are given for believing that the recorded cases of poisoning are not due to the specific action of the drug after absorption, but to the effect of the drug in facilitating certain local reflexes principally of a respiratory nature in the predisposed. "Autoagglutination of Red Blood Cells in Trypanosomiasis." By Dr. W. YORKe. Autoagglutinin exists in small quantity in the blood of many normal animals. It is frequently present in much greater quantity in the blood of animals infected with trypanosomes. Reaction between autoagglutinin and erythrocytes takes place only at low temperatures. The strongest reactions are obtained when a suspension of washed erythrocytes in normal saline solution is treated at o° C. with plasma, which has been prepared by defibrinating blood at 37° C. Autoagglutinin can be removed from plasma by absorp tion with the erythrocytes of the same animal. The reaction between autoagglutinin and red blood cells is reversible, the clumps disappearing on warming and reappearing on cooling. Iso- and hetero-agglutinin are also often present in much greater amount in the blood of infected animals than in that of normal animals of the same species, indicate that auto-, iso-, and hereto-agglutinin are not different highly specific substances, but have closely related affinities. That a clumping together of the red blood cells is frequently observable in coverslip preparations of the fresh blood of animals and man infected with trypanosomiasis, is due to the existence of an excess of autoagglutinin in the plasma, which reacts with the erythrocytes to a certain extent at the temperature (15-20° C.) at which the preparations are usually made. It is to be inferred from the information at present available that a marked degree of autoagglutination of red blood cells is an extremely rare occurrence apart from an infection with trypanosomes. The phenomenon is therefore of some value as a diagnostic sign. Contrary to the accepted view, it was found that the so-called ripening of cheese is not accompanied by a transformation of proteids into fats. The increase of weight of the latter, as observed by other workers, being due to the presence of free cholesterol, aminovaleric acid, putrescine and cadaverine in the ethereal extract. This investigation disproves one of the frequently quoted evidences in favour of the theory that proteids serve as a source for the fatformation in the animal body. "Action of X-rays on the Developing Chick." By J. F. GASKELL, M.A., M.B. No difference was observed in the action of X-rays upon any one tissue rather than another. The action is confined to the lowering of the mitotic activity of the growing tissues. If this diminution is not too great, complete recovery occurs, and the chicks hatch out at the usual time. If the diminution is above a certain degree, recovery does not take place, and further development is arrested forthwith. The critical dose, which just prevents recovery, varies with the stage of development of the embryo, decreasing as the mitotic index decreases. The "mitotic index " as defined by Minot represents the number of mitoses per 1000 cells in the various tissues of embryos of various ages; and he has shown that throughout embryonic life a rapid diminution of mitotic activity is going on. He calls the figures obtained the mitotic index for that particular tissue. "Experiments to Ascertain if Antelope may act as a Reservoir of the Virus of Sleeping Sickness (Trypanosoma gambiense). By Colonel Sir DAVID BRUCE, C.B., F.R.S., A.M.S.; and Captains A. E. HAMERTON, D.S.O., and H. R. BATEMAN, R.A.M.C. (Sleeping Sickness Commission of the Royal Society, Uganda, 1908-10). It is known that the tsetse flies (Glossina palpalis) around the northern shores of the Victoria Nyanza still retain their infectivity for sleeping sickness, in spite of the fact that the native population was removed from the Lake-shore some three years ago. A series of experiments was, therefore, carried out to ascertain if the antelope, which are fairly common along the uninhabited shores of the Lake, were capable of acting as hosts of the parasite of sleeping sickness. Eleven antelope of the waterbuck, bushbuck, and reedbuck species were obtained from a district where tsetse flies and sleeping sickness did not exist. Blood from these animals was first inoculated into monkeys to ascertain if they were already naturally infected with trypanosome disease. They proved to be healthy in this respect. Tsetse flies (Glossina palpalis) that were known to be infected with the virus of sleeping sickness were then fed upon each of the eleven antelope. After about eight days the blood of these animals was again inoculated into susceptible animals, with the result that the latter became infected with Trypanosoma gambiense in every case. In eight out of the eleven buck under experiment Trypanosoma gambiense appeared in their blood for a few days only (some seven to twelve days) after they had been bitten by infected flies. Flies that were hatched out in the laboratory, and had never fed before, were now fed upon the infected antelope, and subsequently upon monkeys. After an interval of about thirty days, required for the development of trypanosomes within the fly, monkeys were infected with sleeping sickness from the antelope by the agency of Glossina palpalis in sixteen out of twenty-four experiments. Ôn dissecting the flies which had been fed upon the infected antelope it was found that 10-8 per cent of them were infected with Trypanosoma gambiense. The highest percentage of infected flies in any one of the positive experiments was 21 per cent; the lowest was 1.3 per cent. Nine of these antelope infected with Trypanosoma gambiense were under daily observation for over four months. They remained in perfect health. Two of them (a waterbuck and a bushbuck) never showed trypanosomes in their blood although examined every day. Both these antelope-infected flies fed upon them, one of them as long as fifty-five days after its infection. No wild antelope inhabiting the Lake-shore has yet been found to be naturally infected with Trypanosoma gambiense. "Experiments to Ascertain if the Domestic Fowl of Uganda may act as a Reservoir of the Virus of Sleeping Sickness (Trypanosoma gambiense)." By Colonel Sir David Bruce, C.B., F.R.S., A.M.S.; and Captains A. E. HAMERTON, D.S.O., and H. R. BATEMAN, R.A.M.C. (Sleeping Sickness Commission of the Royal Society, Uganda, 1908-10). There is evidence that tsetse flies (Glossina palpalis) feed on the blood of birds as well as that of mammals inhabiting the shores of Victoria Nyanza. Domestic fowls, as representing birds, were experimented with in the search for possible hosts or reservoirs of the virus of sleeping sickness. A series of twenty-one experiments was carried out to ascertain : NOTICES OF BOOKS. The Encyclopædia Britannica: A Dictionary of Arts, Sciences, Literature, and General Information. Eleventh Edition. Cambridge: At the University Press. 1910. WE have received for review the Eleventh Edition of the Encyclopædia Britannica. In this first notice we propose to give a preliminary survey of the work as a whole, and to point out a few instances in which it differs from its predecessor the Tenth Edition. Turning over the pages and comparing articles on similar subjects, it is obvious that an enormous advantage has been gained by the simultaneous preparation and publication of the whole Encyclopædia as one complete work. This is the first time such a brilliant feat has been attempted, and, indeed, without a system of perfect organisation, direction, and supervision equal to the generalship in an active military campaign, backed by inexhaustible funds, such a task would have been impossible. "The man behind the gun" is the one to whom success is due; to the Editor-in-Chief, Mr. Hugh Chisholm, we owe the successful accomplishment of this gigantic undertaking. For all practical purposes the whole field of human knowledge is concentrated into 29 volumes. A century ago it would not have been difficult to find a man with a considerable if not profound command of all the sciences. To-day such a feat is impossible; but if the saying is true that next to knowing a thing one's self the next best thing is to know where to put one's hand on the information, the owner of this Encyclopædia for practical purposes may consider himself the master of all knowledge. The rest is only a matter of intelligent reading and memory. The excellent scientific essays in the last editionwhere attempt was made to combine under one heading all, or nearly all, the subjects belonging to the science under discussion - have now been abandoned in favour of the more useful arrangement of sub-branches of the science under the alphabetical headings where the student would be most likely to look for them. To give a general illustration of the treatment of scientific subjects in the Eleventh Edition and how it differs from the plan followed in the Tenth Edition, we will take the subject "Chemistry." Under this heading, in the Eleventh Edition, the science is discussed as a whole, its history and general aspects in relation to other subjects are examined; but the details of the separate branches falling within the subject matter of Chemistry are given in separate articles, to which crossreferences in the general article "Chemistry" act as pointers. For instance, in the old edition the subject "Alkali Manuread through 120 pages of the article "Chemistry." But facture" had no separate heading, and the student had to the present edition contains a special article on "Alkali newly-drawings of the most recent machinery and furnaces. Manufacture" running into 11 pages, fully illustrated with 1. If these birds can, like antelope, be infected with 2. If birds so infected can transmit the parasite to About 2000 flies, many of which had been proved to be infected with virulent Trypanosoma gambiense, were fed upon twenty-one domestic fowls. The results were negative in every case, as ascertained by frequent microscopical examination of peripheral and centrifuged heart's blood, and inoculations of the fowls' blood into susceptible animals. Four hundred newly-hatched flies were fed upon three of the fowls which had been bitten by infected flies. The former were subsequently fed upon monkeys, with the result that they failed to convey sleeping sickness from fowls to monkeys. Two hundred and eighty-three of these flies were dissected, and no flagellates could be found in them. Conclusion.-The Uganda fowl cannot act as a reservoir of the virus of sleeping sickness. "Chemistry" commences with a section on the "History of Chemistry"; followed by one on the "Principles," providing an introduction to the terminology of Chemistry. Then come sections on "Inorganic Chemistry," "Organic Chemistry," Analytical Chemistry." and "Physical Chemistry." The general subject of "Chemical Action" is written by W. Nernst, whilst "Chemistry " is from the pen of C. Everett. Under each subject are numerous crossreferences, among which we may pick out such different departments of the Science as Alchemy, Calorimetry, Capillarity, Crystallography, Electrolysis, Electro-metallurgy, Energetics, Fluorescence, Isomerism, Photochemistry, Refraction, Radio-activity, Spectroscopy, Stereoisomerism, Thermo-chemistry, Thermodynamics, and Valency. Among subjects more closely connected with the practice of Chemistry references are given to articles on Adulteration, Acid, Atom, Condensation of Gases, Distillation, Element, Indicators, Molecule, Medicine, Solution, and Weighing Machines; whilst among chemical bodies |