quired a metallic deposit, then, after well washing, and drying it, the following steps must be resorted to in order to determine the nature of the metallic coating. Diagnosis of Arsenic and Antimony. The copper foil is placed in a tube, which is closed at one end, and heated. A grey or dark metallic ring deposited at the cold part of the glass tube, consists of arsenic. A white sublimate deposited beyond the black ring, and seen under the microscope to consist of cubes and octahedra, is arsenious acid. Antimony is not sublimed under these circumstances. The copper foil is placed into a concentrated alkaline solution of hypochlorite of soda; the metallic deposit of arsenic is immediately or slowly dissolved. The presence of small quantities of antimony does not interfere with this reaction, any further than that the antimony remains undissolved. If the copper foil, after having undergone the above tests, still retains a metallic coating, it is boiled in a weak solution of potash, the metal being partly exposed to air by drawing it out of the alkaline liquid, and then again returning it. In this way the antimony is oxydized by the air in contact with an alkaline solution, and antimoniate of potash is formed. In about five or ten minutes, the copper will have lost the deposit, and the liquid may then be filtered, acidulated with hydrochloric acid, and treated with sulphuretted hydrogen. The persulphide of antimony, of its characteristic colour, is orange-red thrown down, either immediately, or on allowing the liquid to stand for a short time. (Watson). 3. LEAD. Kletzinsky's Method of obtaining Lead from the Urine of patients labouring under Lead poisoning. It is necessary to employ not less than one day's urine for this operation, which is the more likely to be successful, the larger the quantity of urine employed. The urine, after being made alkaline by caustic potassa, is mixed with two per cent. of its weight of nitrate of potassa, and evaporated to dryness. The residue is now transferred into a small china capsule, and exposed to red heat, when a Wien. Med. Wochenschrift,' 1857, No. 42, 44, 45. slow deflagration destroys the whole amount of organic matter present. On cooling, there remains a white slaky mass, not adhering to the capsule, and containing all the inorganic fixed ingredients of the urine together, with the lead that may have been present. This slake is powdered finely, and boiled for some time with a half-saturated solution of neutral tartrate of ammonia, to which some caustic ammonia has been added. The decoction is freed from the residue by filtration; the filtrate contains all the lead in solution. It is acidulated by means of hydrochloric acid, and a current of sulphuretted hydrogen is allowed to pass through it. A brown discoloration, or a black precipitate, indicates the presence of a poisonous metal, which from the history of the case may be supposed to be lead. The precipitate is allowed to deposit for twenty-four hours, washed by decantation, redissolved in warm dilute nitric acid, and the filtrate from the precipitate of sulphur, after neutralization, is tested by means of chromate of potassa and sulphuric acid. The chromate yielding a yellow, the sulphuric acid a white precipitate, excludes any doubt as to the black precipitate having been sulphuret of lead. In fourteen cases of distinct lead poisoning examined in this manner, Kletzinsky succeeded only in two, in proving the presence in the urine of lead by the latter tests. In the twelve remaining, the presence of lead was only indicated by the brownish colour produced in the acid solution by hydrothion. A plumber, æt. 34, was admitted into St. Mary's Hospital, under the care of Dr. Chambers, on the 7th of January, 1857. He had had colic three or four times previously, but had experienced no symptoms of saturnine paralysis. On the 7th of January, he was suddenly attacked with epileptic fits. He had a succession of fits, which lasted for thirty-six hours. When Dr. Sieveking saw him, on the 14th of January, he stated that he had no recollection of anything that happened from the time of his admission into the hospital to the 12th of January; that he woke up with severe headache, occupying the entire head, with vertigo, and found that he had lost the power of moving the left leg and the right arm; the left arm and the right leg continued normal both in regard to sensation and motion. There was decided diminution of sensation in the affected limbs, and the right hand was in a permanent semi-flexed condition, with very little power remaining of opening or closing the fingers. On first recovering consciousness, the people in the ward seemed to him as small dolls, and the opposite side of the room seemed to be sunk forty feet below its own level. These erroneous impressions he was conscious of at the time, and they disappeared in four days. The urine was very scanty. There was a marked blue line round the margin of the upper and lower gums. There had been a suscepti. bility to pain in the paralysed parts, which remained after the ordinary tactile sensibility appeared to be restored. On the 10th of January, the patient had 10 grains of iodide of potassium administered to him three times a day. A rapid improvement was perceptible. The amount of urine rapidly increased; but although on two occasions after commencing the iodide of potassium, the urine of at least twelve hours was tested for lead, none was found. The fact that Dr. Bernays, the able chemical lecturer at St. Mary's Hospital, kindly charged himself with these analyses, will be a sufficient guarantee that no lead was present. Dr. Sieveking again ordered the urine to be collected from the 20th to the 21st of January, and although probably only about one half of the urine secreted had been preserved, owing to the remainder having been discharged in defecation, he obtained 860 c.c., of a reddish-yellow hue, and turbid. This was evaporated down nearly to dryness, and the residue was boiled with nitro-hydrochloric acid, and filtered. The filtrate, on the addition of sulphide of ammonium, or of sulphuretted hydrogen, gave a copious precipitate of the sulphuret of lead.-Dr. Sieveking, Med. Times and Gaz,,' Feb. 14, 1857. 4. MERCURY. The urine is treated on the water-bath with chlorate of potash and fuming hydrochloric acid, until the chlorate and organic matters are entirely destroyed. The fluid is then evaporated to dryness, and the residue extracted with ether, until this solvent does not take up anything more. The ethereal solution, on evaporation, leaves dry mercury in the form of chloride, or corrosive sublimate. The watery solution of this latter is precipitated yellow by caustic potassa, and the precipitate is insoluble in an excess of the alkali. Iodide of potassium produces a fiery red precipitate of iodide of mercury, soluble in an excess of the iodide of potassium. In all cases, where the urine contains mercury, there is at the same time a peculiar albuminous substance present in it, which with nitric acid gives a faint reaction of albumen. A substance is also present, having the reactions of sugar. Not in all cases of mercurialism has it been possible to detect the metal in the urine. In some cases, the metal only appeared in the urine at intervals, even where the symptonis had undergone no remission. In other cases, the reappearance of the metal in the urine was accompanied by a decided increase in the severity of the mercurial symptoms. 5. COPPER. The urine is treated on the water-bath with chlorate of potash and fuming hydrochloric acid, until the organic matters and the chlorate are entirely destroyed. The pale yellowish solution is now made alkaline by an excess of ammonia, whereby its colour changes into brown, with a smoky hue. Any precipitate that may ensue is removed by Kletzinsky, Wien. Med. Wochenschrift,' 1857, No. 43. filtration. The filtrate is evaporated on the water-bath to perfect dryness, the residue moistened with nitric acid of 1.5 specific gravity, and exposed to red heat in a china capsule. The ashes, which must not contain any charcoal, are dissolved in hydrochloric acid, and this solution is boiled under addition of little nitric acid, in order to ensure the highest possible oxydation of the metals, iron and copper, of which the former is always present in urine. This acid solution is now treated with excess of ammonia, whereupon a precipitate of hydrated oxyde of iron falls down, which must be removed by filtration. If the filtrate has a bluish colour, and after being acidulated with acetic acid, yields a reddish turbidity or reddish-brown precipitate with ferrocyanide of potassium, the presence of copper is proved. This proof may be further strengthened by acidulating the alkaline solution by hydrochloric acid, and conducting a current of sulphuretted hydrogen through it; a brownish turbidity, soluble in sulphuretted ammonium, with a brown colour, is indicative of copper. Another test consists in putting a piece of blank iron foil, surrounded by a spiral wire of platinum, into the solution, acidulated by hydrochloric acid. After several hours, the iron is covered by a red hue, if copper is present in the solution. In six cases of poisoning by copper compounds, noticed by Kletzinsky, this metal could be found in the urine as long as any symptoms remained about the patients. When the symptoms ceased, the copper disappeared from the urine, but continued to be discharged with the fæces. The fæces of healthy persons mostly contain some copper; healthy urine, however, does not contain any traces of this metal. Of other inorganic substances introduced into the system, the following have been found to make their appearance in the urine: Bromine (Heller), and bromides. Ammonia, mostly as such, a small quantity transformed into nitric acid. (Bence Jones.) |