IV. CHEMISTRY. IN commencing the Chronicles of the progress of Science for the last few months, it becomes necessary to exercise considerable care in the choice of subjects to be mentioned, so as to avoid on the one hand the omission of anything likely to interest a large section of our readers, and on the other hand to keep our pages from being overburdened with a mass of facts, important, no doubt, to the student of one special science, but of no interest to those outside the circle. This precaution is especially necessary in a science like Chemistry, in which not only does every month bring forth new discoveries, but every week-nay, every day is marked by some valuable fact. Our readers must not therefore expect to find every fact, even those most important, recorded in these chapters, but it will at the same time be our endeavour so to select our topics as to constitute these pages a truthful mirror of the general progress of Science. * There have been few periods more fruitful in important chemical discoveries than that comprised within the last few months. Two new metals have been announced as belonging to the already numerous family of elementary bodies, one of which has been literally brought to light by spectrum analysis—that powerful analytical process which has already given us cæsium, rubidium, and thallium. The new arrival is due to the labours of two German chemists, F. Reich and T. W. Richter. They were examining some impure chloride of zinc obtained from two Freyberg ores, in the expectation of finding thallium present. In the spectroscope no green line was seen, but the authors remarked an indigo blue line, which was till then unknown. Upon isolating the conjectural substance in the form of chloride, they found that it gave this blue line, so brilliantly sharp and persistent, that they at once came to the conclusion that it belonged to a hitherto unrecognized metal, to which they accordingly gave the name indium. In their memoir the authors give the characteristic properties of the new metal, which appears somewhat to resemble zinc, and describe several of its compounds. The discovery has been confirmed by other chemists of eminence, and there now appears to be no doubt whatever as to its accuracy. The same cannot be said respecting the new metal claimed by M. J. F. Bahr.† In the analysis of a highly complicated mineral, from the island of Röusholn, containing nearly all the metals of the aluminium group, the author obtained about 1 per cent. of what he supposed was a new addition to this numerous family. He proposes for it the name of wasium. The existence of wasium as a simple body has been since disputed by M. Nicklès, who asserts it to be a mixture of the known bodies yttrium, didymium, and terbium. *Journal für praktische Chemie,' bd. lxxxix. p. 441. † Annalen der Physik und Chemie,' vol. cxix. p. 572. Comptes Rendus,' Nov. 2. The already known elementary bodies are being gradually brought within the domain of spectrum analysis. Phosphorus, which has been long known to communicate, under some circumstances, a green colour to flame, has been shown by MM. Christofle and Beilstein* to possess a very definite spectrum, consisting of three distinct green lines. This new test is likely to be of considerable use, as, by its means, this deleterious body has been shown to exist in many samples of good commercial iron, which were supposed to be free from this impurity. Our knowledge of the recently discovered element, cæsium, has been greatly enlarged by its discoverer Bunsen.† For the original isolation of this interesting alkali, nearly 100,000 lbs. of the mineral water of Dürkheim were evaporated down, yielding, however, only 30 to 40 grains. He has since determined the atomic weight to the metal with great accuracy upon a somewhat larger quantity, and has obtained the same number as those given by Messrs. Johnson and Allen, ‡ namely 133. M. Rose has announced a no less important discovery than that of an entirely new series of metallic oxides. § In his memoir he proposes a new nomenclature which, were it generally adopted, would be of great convenience to chemists. The new series, which he has discovered, consists of 1 of metal with of oxygen, and this he proposes to call quadrantoxide; the compound of 1 of metal with of oxygen, variously named the suboxide or the protoxide, he proposes to call semioxide; the compound of equal atoms of metal and oxygen he calls isoxide; the compound of 1 of metal to 13 of oxygen retains its name, sesquioxide; whilst the ordinary binoxide is called the diploxide. Only one quadrantoxide has as yet been formed and analysed, but reasons are given for supposing that the suboxide of silver is really the quadrantoxide, and it is very probable that quadrantichlorides of the alkali metals are also known. As might be expected from their composition, these new oxides are difficult to prepare, and are easily decomposed. The mysterious body ozone, respecting which so much has been done but so little is known, is still occupying the attention of chemists. Schönbein has already shown that this body is formed when evaporation takes place, and M. Morin || considers that the good effects observed when water is artificially evaporated during the ventilation of rooms, may be due to the formation of a certain quantity of ozonized oxygen. English writers on Ventilation always advocate the introduction of a certain amount of moisture into the air supplied to inhabited places, and this has been well carried out in the ventilation of the Houses of Parliament. Few chemical manufactures have been developed so much of late years as that of the barium compounds, and its prospective applications are most numerous and important, although at the present day their 'Comptes Rendus.' use seems to be confined to the manufacture of green fire. M. Kuhlmann has lately entered very largely into the manufacture of different compounds of barium, with a view to their commercial introduction. The absorption of oxygen from the air by red-hot baryta, and its subsequent release at a higher temperature, in the form of pure gas, could be made of the greatest importance to metallurgical and furnace chemistry. A cheap method of making peroxide of barium would place us in possession of the valuable peroxide of hydrogen, which would be of incalculable use as a disinfectant, and also in many manufacturing processes. To the industrial chemist cheap caustic baryta would entirely revolutionize the alkali manufacture, whilst for many purposes it would supersede the ordinary alkalies. In the manufacture of crystal-glass, lead, the most costly ingredient, could be even now economically replaced by a barium compound, provided a few preliminary difficulties were overcome. Nitrate of baryta can also be economically employed in the preparation of blasting powder; the chromates of baryta can in many cases replace the more costly chromates of potash, and the same may be said of the ferrocyanides, all of which are largely used in dyeing. These are some of the more important applications of this earth, but an immense number of minor uses has also been proposed, and there is little doubt that it will shortly become as valuable in industrial as it already is in analytical chemistry. The extraordinary prolificness of some organic chemists in the discovery of new bases, will cease to be surprising after the perusal of a paper by Mr. Broughton,* in which it is shown that the known general processes for their formation are competent to produce several sextillions of new ammonias. As most, if not all, of these compounds only require for their production certain known agents to be placed in contact, it is evident that chemists need not debar themselves from the title of original discoverers for lack of virgin soil on which to work. The value of the element bromine in the arts and manufactures is daily increasing, and were its price reduced, its importance in many industrial operations can scarcely be over-estimated. Hitherto the only source has been sea-water, where it exists in the form of bromide of magnesium, one part of this salt being dissolved in 100,000 parts of water. Recent experiments, by M. Roux,† show that the water of the Dead Sea is more than 100 times richer in bromine than ordinary sea-water. Already we hear of proposals for the establishment of a factory near the Dead Sea, for the separation of this element. It is much to be desired that this inexhaustible store of so valuable an agent should be utilized. Perhaps the most important point to determine in the analysis of a drinking water is the presence of nitric acid, as this body is so closely connected with putrescent organic matter. Hitherto, however, few chemists take note of it, owing, doubtless, to the difficulties which beset its detection when very dilute. Mr. R. Kestings has now * Chemical News,' vol. viii. p. 245. + Comptes Rendus,' vol. lvii. No. 14. 'Annalen der Chem. und Pharm.' shown that the alkaloid brucine is a most delicate test for nitric acid, being coloured rose-red by water, containing only the 100,000th part. It is to be hoped that more attention will in future be paid to the varying proportions of this acid in potable water, and that the warnings given by its presence will not be disregarded. The subject of pure water for household purposes is so important that we again recur to it, to notice an invention of Dr. H. Schwartz, which appears to remedy perfectly the effects of the employment of lead pipes and cisterns. He converts the inner surface of the metal into an insoluble sulphide by boiling in it a solution of sulphur in soda. The result is that the water is perfectly kept from contact with the metal, and will be as free from contamination as if it had been passed through a glass pipe. Some curious results of the inhalation of the vapour of glonoine (an oil obtained by the action of nitric acid on glycerine) have been given by Mr. Merrick.* It has long been known that this body produces violent headache, but these experiments show that it is a most powerful agent in its physiological action. In one case the fortieth part of a drop dissolved in spirit was swallowed on a piece of sugar. In two minutes the pulse had risen considerably, being accompanied Iwith a violent headache. This continued for nearly half-an-hour, when the symptoms passed off. At another time, when a quantity of vapour was accidentally inhaled, the headache became almost intolerable, and was accompanied by a good deal of faintness and exhaustion, intolerance of light, and a feeling of great general distress and alarm. The violent toxical effects show that glonoine is a powerful poison, and, like most agents of this kind, will doubtless be employed in medicine. The application of gun-cotton as a substitute for gunpowder in warfare has occupied the attention of a committee of scientific men for some time past. General Von Lenk, of the Imperial Austrian Artillery, has invented a system of preparation by which gun-cotton has been made practically available for warlike purposes. The committee have had the advantage of personal communication with the General, and in the report, which will shortly be issued, an abstract of which having been communicated to the British Association at Newcastle, we are promised a vast amount of information of the most important character. General Von Lenk has shown that perfect guncotton is a definite chemical compound; he has given accurate processes for its manufacture, and for the removal of all extraneous matter and traces of free acid. As thus prepared, it is no longer liable to spontaneous combustion, it can be stored for any length of time without deterioration, it is not impaired by damp, and may be immersed in water without injury, its original qualities returning unchanged when allowed to dry in the air. These are valuable properties, and when we add to them the absence of smoke, the entire freedom from fouling, the innocuous character of the products of combustion in com, *Silliman's Journal,' vol. xxxvi. No. 107. parison with those of gunpowder, and the far inferior heat imparted to the gun itself, it will be seen that the advantages attending the employment of gun-cotton, are so many and so important as to call imperatively for the fullest investigation. From gun-cotton to armour-plated ships is a natural transition in these warlike days. Science seems to be at fault on the subject of the preservation of iron plates from oxidation and fouling. One of the best processes, that has yet come under our notice, is due to Messrs. Johnson and Calvert. They propose to coat the iron with a thin layer of metallic zinc, as in the ordinary process of galvanizing. Their results prove that the film of zinc exercises a great protective power against the corrosive action of sea-water; upwards of a year's exposure showing that four or five times as much corrosion took place in the case of uncoated as with galvanized iron plates. Whether galvanizing would prevent fouling, remains to be seen; we suspect it would rather aggravate this evil. V. GEOLOGY AND PALEONTOLOGY. THERE is perhaps more difficulty in describing the periodical progress of Geology, than there is in recording that of any other science. The exactitude of the advance is less decided, the views set forth more speculative, and the facts given more open to objection or discussion, than is the case in any other department of intellectual investigation. In Chemistry, the discovery of an element or of some previously unknown compound, gives a fixed and tangible point from which to go onward to further knowledge. Every step is a permanent score in the continuous tally. So the discovery of a comet or a planet, or a nebula, or more exact measurements of angles, or of distances, or the detection of errors of observation, or calculations or the revelations of increased telescopic powers, all yield for Astronomy definite and incontrovertible results, and it is only in the special sphere of absolutely speculative Astronomy, that there is any uncertainty whatever. So, too, in Botany, a new flower, or a flora of some previously unnoticed region, is so much substantially added to the previous knowledge, so much gain which can be appreciated and recorded. But in Geology, we have to deal with the rags and shreds of former ages and former beings, nothing whole or entire,-every relic has to be dug out of the débris and ruins, which we have, as it were, first to clear away before we can get a glimpse of any treasures remaining beneath, and when we find these they are damaged and mostly broken fragments which we have to join and fit, and put together, to get, in the best way we can, some general notion of what they originally were. Thus it is a new geological idea gets started, and is discussed, opposed, supported, until finally substantiated or disproved; in short, it is only after a contest that, generally speaking, any progress in this science is admitted. In |