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to matter are the effects of powers necessarily inherent in bodies, and without which they cannot exist. These opinions he maintained without any reserve, and brought them forwards in his writings when the subject appeared to call for them; but it does not seem that he took any particular pains to make converts to these doctrines, or was more anxious to impress them upon the minds of his readers, than any other of his opinions. They were regarded by him as lying at the foundation of his speculations, but in no other respect as being of any peculiar moment. The great phenomena of attraction and repulsion he supposed to depend upon the afflux and efflux of certain subtile fluids to and from bodies, which, as it were, carried other bodies along with them in their current. He seems to have regarded Galvanism as the most powerful agent in nature, or rather the prime cause of all the changes that are perpetually going forwards around us; he not only speaks of it as the first step in all physical and chemical operations, but he extends its influence to the vital properties of sensibility and muscular contraction. In his arrangement of natural objects he recurs to the antiquated division of them into four elements: under the denomination of fire he includes, not only caloric, but the other imponderable fluids, light, electricity, and magnetism. With respect to air, his ideas do not seem to have been well defined; but it may be conjectured that he regarded oxygen, or, as he termed it, pure air, as the basis of all the other gases, and that they were formed by the combination of this with some other substance. Water he regarded as an undecomposable body, the ponderable part of air; and of course in all those processes where water is supposed to be generated by the combination of oxygen and hydrogen, the water was conceived to be merely an educt, not a product, He remained to the last a firm opposer of the antiphlogistic theory, and triumphed not a little in the latter part of his life, when he observed that the fundamental doctrines of Lavoisier were called in question, or controverted by subsequent experiments. This was particularly the case with respect to the doctrine that acidity necessarily depends upon oxygen; yet his opinion, which he wished to substitute in its room, that acidity essentially depends upon fixed or condensed heat, is much more hypothetical, and less intelligible.
Delametherie perhaps excelled the most as a geologist and mineralogist; and on these topics, contrary to what we often find to be the case, his opinions are the best matured, or at least his speculations are more plausible. He conceived that every part of the globe had at some period of its existence been in the liquid state, and that the waters had formerly covered the highest mountains; but it does appear that he adopted exclusively either of the hypotheses which have divided geologists into the two rival sects of the Volcanists and the Neptunists. Mineral substances he divided into 10 classes; gases, waters,
combustible non-metallic bodies, combustible metallic bodies, acids, alkalies, earths, salts, volcanic substances, and fossils. It has been already observed that he disapproved of the plan of making crystalline forms the basis of a mineralogical system: this he regarded as one only among other properties which ought to be employed for this purpose.
His most singular opinions were those on organized bodies: he supposed that they were originally produced by the crystallization of their seed; that their vital powers depend upon Galvanism, which is evolved by the superposition of alternate strata of medullary and muscular parts; that there is a strict analogy between animals and vegetables, both in their structure and functions; and that there is no part or property in one of these classes to which a corresponding part or function may not be demonstrated in the other. As his mineralogy is the best, so it may be asserted that his physiology is the worst part of his works; it abounds the most with mere speculation and false analogies, and is the least supported by absolute facts or correct deductions.
We may sum up our remarks upon the character of Delametherie by saying, that he possessed many valuable qualities, both moral and intellectual, but that, along with these, he had some natural defects of temper and disposition, which were unfortunately fostered by his acquired habits, so as, in a considerable degree, to destroy both his happiness and his utility. Upon the whole he must be regarded as a man more to be respected than esteemed, who, although ardently bent upon the promotion of science, and indefatigable in the pursuit of it, accomplished much less than might have been expected from the same portion of talent and industry, had they been differently directed, and placed under the controul of a better regulated judgment.
On Phosphuretted Hydrogen, By J. Dalton.
(To Dr. Thomson.)
Manchester, Nov. 16, 1817. HAVING been lately engaged in investigations on the phosphurets, I had to review the experience of others, as well as my own already published, relating to phosphuretted hydrogen gas, and to make very material corrections and additions. I hasten, therefore, to communicate the facts observed, without going into detail of experiments, that others may, if they choose, avail themselves of the train into which I have been led.
1. There is but one combination of phosphorus and hydrogen, as far as can be deduced from experiments hitherto made; all the varieties of phosphuretted hydrogen have arisen from the circumstance that free hydrogen is liable to be produced less or more in all the processes used for the generation of phosphuretted hydrogen.
2. Phosphuretted hydrogen may be obtained in great purity from phosphuret of lime by the method recommended by Dr. Thomson (Annals of Philosophy, vol. viii. p. 89), provided the phosphuret has been well secluded from the atmosphere; but if it has been previously exposed for a few hours to the atmosphere, the gas will be much more copious, and contain from 50 to 80 per cent., less or more, of free hydrogen, and only the rest phosphuretted hydrogen.
3. Pure phosphuretted hydrogen may easily be withdrawn from hydrogen by liquid oxymuriate of lime; it absorbs the former gas, and converts it into phosphoric acid and water, almost as readily as green sulphate of iron absorbs nitrous gas; and the latter or free hydrogen is left unaffected.
4. Pure phosphuretted hydrogen may be mixed with safety in narrow tubes (of an inch diameter) with pure oxygen; and in due time the mixture may be transferred into any sort of vessel without explosion, and kept many hours without any sensible chemical action. An electric spark fires it instantly, with a violent explosion and a brilliancy surpassing that of any other gas. Prudence requires that very small portions of the mixture should be exploded; with a strong tube having the glass of an inch thick, I do not think it safe to explode more than 15 water grain measures of phosphuretted hydrogen at once.
5. One volume of phosphuretted hydrogen requires, as nearly as I have ascertained, two volumes of oxygen for its complete combustion. Phosphoric acid and water are formed.
6. Pure phosphuretted hydrogen, by being electrified for one or two hours in duc quantity, expands nearly of its original volume. Phosphorus is deposited, and the residual gas is hydrogen mixed with less or more of phosphuretted hydrogen which may have escaped decomposition, and which is determinable by exploding with oxygen. If any atmospheric air be present (which is almost unavoidable in the small quantity of five or six per cent.), at first electricity perceptibly diminishes the gas; but it soon begins to expand, though in that case it can scarcely be made to exceed 25 per cent. on the first volume. 7. Water freed from air absorbs fully of its volume of this gas. This was first announced by Sir H. Davy, of what he calls hydrophosphoric gas, which appears from this and other properties to have been nearly pure phosphuretted hydrogen. The gas, I find, is capable of being expelled again by ebullition, or by agitation with any other gas in the usual way, but not without a loss of less or more phosphorus.
8. One volume of pure phosphuretted hydrogen mixed with from two to five volumes of pure nitrous gas afford a most brilliant explosion by one or more electric sparks, as was discovered by Dr. Thomson. When duly proportioned (I find 1 to 31, and not 1 to 3, as Dr. Thomson), the result is phosphoric acid and water, with azotic gas two or three per cent. less than the volume of nitrous gas. When more or less than 34 of nitrous gas is used, the residue of gas after the explosion contains oxygen gas or hydrogen gas accordingly; rarely any phosphuretted hydrogen. Dr. T. says that no alteration is produced by mixing nitrous gas and phosphuretted hydrogen. This is correct if we are to understand immediately; but not otherwise: for, by standing one, two, or three hours, the whole phosphuretted hydrogen is consumed (if the nitrous gas be in excess), and there is left a mixture of nitrous gas, nitrous oxide and azotic gases, amounting to about half the volume of the original mixture. Dr. T. found that a bubble of oxygen causes a mixture of nitrous and phosphuretted hydrogen to explode; by analogy I concluded that a mixture of phosphuretted hydrogen and oxygen would explode by a bubble of nitrous gas, and found it accordingly.
9. Nitrous oxide and phosphuretted hydrogen explode by a spark, but undergo no change by simple mixture for several hours at least. The due proportions are nearly three to one.
Experiments on phosphuretted hydrogen are most likely soon to determine the controverted question respecting the constitution of phosphoric acid, as well as those concerning the quantities of azote and oxygen in the nitrous compounds. I remain yours,
Some Account of a late Mission to Ashantee.
IN the "Voyage du Chevalier Des Marchais," published in 1730, by Le Pere Labat, is a map of Guinea drawn by Danville. In this map, between 30 and 40 G. miles north of Cape Coast Castle, is represented the southern frontier of the kingdom of Asianté. Its breadth from west to east is between 50 and 60 miles its northern frontier is not defined. M. Des Marchais makes no mention of this country in his travels (which indeed were confined to the eastern districts of Guinea); but in the map it is called Royaume tres puissant, and is divided into seven provinces.
During the last 80 or 90 years the Ashantees appear to have
been progressively subjecting the districts lying to the south-east between their own territory and the sea, till at length they began to excite the notice and suspicion of the European forts and factories on the Gold Coast. From information transmitted by the Governor of Cape Coast Castle to the African Society, it appears that in October, 1815, the Ashantees were in force at the back of Acra (Acron of Danville), where they remained till the month of May in the following year. At this time a battle took place between them and the people of Adjumacoon and Agoonah, in which the Ashantees were victorious. They then proceeded westward along the coast, driving before them the Fantees, a tribe inhabiting the territory surrounding Cape Coast Castle, and under the protection of the British garrison of that fortress. On June 2, about 4000 Fantees, chiefly women and children, took refuge in the castle, which circumstance induced the necessity of opening immediately a negotiation with the general of the Ashantee army; the result of which was, that peace was restored to the country under protection of the Company; and the Ashantees, having received presents to a considerable amount, quitted the coast about the end of June.
The friendly intercourse which had thus taken place seemed to offer a favourable opening for a direct communication with the King of Ashantee: accordingly the Company sent out instructions to the Governor of Cape Coast Castle authorizing him to dispatch a mission or embassy to Ashantee, which, besides attending to the peculiar interests of the Company, should endeavour to obtain satisfactory information on the nature of the country, the soil and products; the names, distances, latitude, and longitude, of the chief places; the manners of the people; their laws, customs, and government; the objects of commerce, particularly gold and ivory; and, if possible, to procure permission for some children of the chiefs to be educated at Cape Coast Castle.
Three gentlemen (two writers and a medical man) were entrusted with the conduct of the expedition, which set out from Cape Coast Castle on April 21, 1817.
After a circuitous route, calculated at from 150 to 200 miles, the embassy arrived at Cormarçie, the capital, and experienced a very favourable reception from the King. Their intercourse was of necessity at first carried on through the dubious medium of interpreters; but the envoy in a short time acquired the language of the country, and thus was enabled to open a direct communication with the King. The embassy still remained at Cormarçie when the last vessels sailed from the coast: by these, letters were received from persons of the embassy, and from others, containing various particulars more or less interesting, some of which have found their way into the newspapers, and other periodical publications. One of the editors of this journal has likewise been favoured with the perusal of a communication