Cooley's Cyclopaedia of Practical Receipts Volume Ii Part 158

_Uses._ Platinum is valuable for the formation of crucibles, capsules, and other utensils or instruments intended to be exposed to a strong heat, or to the action of acids. Platinic chloride and the platinic and sodium chloride are much used in chemical a.n.a.lysis. Both of these are also used in medicines with the same intentions, and in the same doses, as the corresponding salts of gold. These compounds are poisonous. The antidotes and treatment are similar to those described under GOLD.

_Concluding Remarks._--Daville and Debray have introduced a method of refining platinum, which has already done much to extend the useful applications of the metal. The process consists in submitting the crude metal to the action of an intensely high temperature, obtained by the combustion of hydrogen (or coal-gas) with oxygen, in a crucible of lime.

By this means large quant.i.ties of platinum (50 lbs. or more) can be kept fused until the sulphur, phosphorus, a.r.s.enic, and osmium, generally occurring in crude platinum, are oxidised and volatilised, and the iron and copper are oxidised and absorbed by the lime forming the crucible. At the International Exhibition of 1862 an ingot of pure platinum, weighing over 2 cwt., was exhibited by Messrs Johnson & Mathey, as an ill.u.s.tration of the practical results of this process.

=Platinic Chloride.= PtCl_{4}. _Syn._ BICHLORIDE OF PLATINUM, CHLORIDE OF PLATINUM, PERCHLORIDE OF P.; PLATINI BICHLORIDUM (Ph. L.), L. PLATINI TETRACHLORIDUM. _Prep._ By dissolving platinum in nitro-hydrochloric acid, and evaporating the solution to dryness at a gentle heat. _Prop., &c._ Reddish-brown, deliquescent, and very soluble in both water and alcohol, yielding orange-coloured solutions. It combines with a variety of metallic chlorides to form 'double salts.' Used as a test in chemical a.n.a.lysis, and as an alterative in secondary syphilis, &c.--_Dose_, 1/16 to 1/4 gr., dissolved in distilled water, or made into a pill with syrup and liquorice powder. Some persons prescribe much larger doses, but unsafely. Hoefer recommends an ointment made with it as an application to indolent ulcers.

In doses of 5 gr. and upwards it acts as a violent caustic poison. This last salt is the 'chloride of platinum' of the shops, and the one used in the arts and medicine. It forms one of the tests included in the Appendix to the Ph. L.

=Platinic-Ammonium Chloride.= Pt(NH_{4})_{2}Cl_{6}, or PtCl_{4} 2NH_{4}Cl.

_Syn._ AMMONIO-CHLORIDE OF PLATINUM, PLATINO-CHLORIDE OF AMMONIUM. _Prep._ A solution of chloride of ammonium is added to a strong solution of platinic chloride, and the precipitate washed with dilute alcohol.

_Prop._ Minute, transparent, yellow octahedral crystals very feebly soluble in water, less so in dilute alcohol, and insoluble in acids; heat converts it into spongy platinum.

=Platinic-Pota.s.sium Chloride.= PtK_{2}Cl_{6}, or PtCl_{4}2KCl. _Syn._ PLATINO-CHLORIDE OF POTa.s.sIUM, POTa.s.sIO-CHLORIDE OF PLATINUM. _Prep._ A bright yellow, crystalline precipitate, formed whenever solutions of the chlorides of platinum and of pota.s.sium are mixed; or a salt of pota.s.sium, acidulated with a little hydrochloric acid, is added to platinic chloride.

In appearance, solubility, &c., it closely resembles ammonio-chloride of platinum.

=Platinic-Sodium Chloride.= PtNa_{2}Cl_{6}, or PtCl_{4}2NaCl. _Syn._ CHLORIDE OF PLATINUM AND SODIUM, SODIO-CHLORIDE OF PLATINUM, PLATINO-BICHLORIDE OF SODIUM; PLATINI ET SODII CHLORIDUM, PLATINI SODIO-CHLORIDIUM, &c., L. _Prep._ (Redwood.) Platinic chloride, 17 parts; chloride of sodium, 6 parts; dissolve the two salts separately in water, q. s., mix the solutions, and evaporate, that crystals may form. The crystals are large, transparent, and of a yellow-red colour.--_Dose_, 1/12 to 1/2 gr.; in the same cases as the bichloride.

=Platinic Oxide.= PtO_{2}. _Syn._ BINOXIDE OF PLATINUM. _Prep._ 1. By exactly decomposing the platinic sulphate with nitrate of barium, and adding pure hydrate of sodium to the filtered solution, so as to precipitate only half the oxide. (Berzelius.)--2. By boiling platinic chloride with hydrate of sodium, in considerable excess, and then adding acetic acid.

_Prop., &c._ As the hydrate (Pt(HO)_{4}), it is a bulky brownish powder; this, when gently heated, becomes black and anhydrous. It forms salts with the acids, and combines with some of the bases. The salts have a red or yellow colour, and a remarkable tendency to form double salts with the alkaline salts.

_Obs._ Both the oxides of platinum are reduced to the metallic state on ignition.

=Platinous Oxide.= PtO. _Syn._ OXIDE OF PLATINUM. _Prep._ By heating to below redness the platinic chloride and digesting with hydrate of pota.s.sium the residue.

_Prop., &c._ A black powder, soluble in excess of alkali, and freely so in the acids, forming brown solutions of the platinous salts. These are distinguished from solutions of the platinic salts by not being precipitated by chloride of ammonium. Platinous oxalate, in fine copper-coloured needles, may be obtained by heating platinic oxide in a solution of oxalic acid.

=Platinum Gas.= _Syn._ GAZ-PLATINE; GILLARD'S GAS. In Paris this gas is employed by gold- and silversmiths and electro-platers because it gives rise to no sulphur product and burns without giving off soot or smoke. It is free from smell. Steam is decomposed by being made to pa.s.s through a retort filled with red-hot charcoal. The hydrogen being freed from the carbonic acid which is a.s.sociated with it, by means of crystallised carbonate of soda, is burnt from an Argand burner provided with numerous small holes. The flame, which is not luminous in itself, is surrounded by a network of moderately fine platinum wire, which on becoming white-hot becomes luminous. It burns quite steadily, and its illuminating power is said to exceed slightly that of coal gas.

=Platinum, Spongy.= _Prep._ 1. By heating ammonio-chloride of platinum to redness.

2. Crude bichloride of platinum and chloride of ammonium are separately dissolved in proof spirit, and the one solution added to the other as long as a precipitate forms; this is collected, and, whilst still moist, formed into little b.a.l.l.s or pieces, which are then dried, and gradually heated to redness.

_Prop., &c._ These have been noticed above. Small b.a.l.l.s of spongy platinum are used for the hydrogen instantaneous-light lamp (Dobereiner's lamp); but they are apt to absorb moisture from the atmosphere, and then lose their power of inflaming hydrogen, until they are re-dried and heated.

=PLEURISY.= Inflammation of the pleura, or membrane covering the lungs.

The symptoms of pleurisy are a sharp pain in the side, which is rendered more acute when a deep breath is taken; quick, short, difficult inspiration; a quick pulse; and fever. Much pain is also experienced if the attempt be made to lie on the affected side.

Pleurisy sometimes accompanies pneumonia or inflammation of the substance of the lungs. If allowed to run on, the disease produces effusion of serum or of lymph into the cavity of the chest, in either case giving rise to adhesions, which cause embarra.s.sment of breathing. On the contrary, it may terminate by resolution or complete recovery.

Pleurisy generally arises from exposure to the cold. A blow or a wound will also cause it, and a not uncommon origin is the splintered end of a broken rib. In every case the advice of the medical pract.i.tioner should be sought upon the first indications of the disease. The following treatment is suggested for adoption only by emigrants, or others unable to procure the services of the medical man in cases of urgency:--

Under these circ.u.mstances the patient, sitting in an upright posture, should be bled until he is able to breathe without feeling pain. If after bleeding the pain should return, leeches, if obtainable, should be applied to the painful part, and a large blister should be placed near the affected spot. After being bled the patient should have a hot bath.

Should the pain not subside, leeching must be had free recourse to, or blood be drawn by cupping. A brisk purgative should be given at the commencement of the disease, and after this has ceased acting the patient should take two grains of calomel and a quarter of a grain of opium every four hours, but this treatment must not be continued longer than is necessary. The patient should remain in bed in a room which has a uniform temperature of 60 F., and adopt a low diet.

IN HORSES.--_Symptoms._ Fever, indicated by shivering, indisposition to move or turn, quick pulse, painful cough, and hurried respiration.

"Place the animal without delay in a cool, airy, loose box, and bleed to the extent of seven or eight quarts, or until the pulse falters. Bleeding is never justifiable after the third day, when the pulse reaches 70. Three or four drachms of aloes in solution will suffice for the horse, and clysters must also be given. Until the physic operates sedatives must be used with great caution. Twenty minims of Flemming's tincture of aconite should be given every three hours.

"Towards the close of the second day the aconite may be discontinued, and a scruple of calomel and a drachm of opium given in a bolus, and repeated every four hours until four or five doses have been given. Apply liniment of ammonia or mustard to the sides. If the animal be thirsty give water in which nitre has been dissolved. Keep the animal perfectly quiet, and let it have soft laxative food." (Finlay Dun.)

=PLUG'GING.= The introduction of a ma.s.s of lint, sponge, or other suitable material, into a wound or cavity, with the intention of arresting haemorrhage. It is now seldom adopted, except in cases of bleeding from the nose, and that only after more approved methods have failed.

=PLUM.= A name applied to several varieties of the _Prunus domesticus_ (Linn.), or wild plum. Among the cultivated varieties, the damson, greengage, French plum, magnum bonum or Mogul p., mirabelle p., Orleans p., and prune, are those best known. Grocers' 'plums' are raisins, or dried grapes.

In the following table will be found the composition of the princ.i.p.al varieties of plum.

+------------------+----------+---------------+-------+-------+----------------+ Greengage. Mussel Plums. Black- Mirabelle,+-------+-------+ blue, Dark +-------+--------+ common Yellow- Large middle- black- Italian, yellow. green, green, sized red Common. very middle very Plums. Plums. sweet. size. sweet. +------------------+----------+-------+-------+-------+-------+-------+--------+ _Soluble matter_-- Sugar 3584 2960 3405 1996 2252 5793 6730 Free acid, reduced to equivalent in malic acid 0582 0960 0870 1270 1331 0952 0841 Alb.u.minous substances 0197 0477 0401 0400 0426 0785 0832 Pectous substances, &c. 5772 10475 11074 2313 5851 3646 4105 Ash 0570 0318 0398 0496 0553 0734 0590 _Insoluble matter_-- Seeds 5780 3250 2852 4190 3329 3540 3124 Skins, &c. 0179 0680 1035 } { 1990 0972 Pectose 1080 0010 0245 } 0509 1020 { 0630 1534 [_Ash from insoluble matter included on weights given_] [0082] [0039] [0037] [0041] [0063] [0094] [0066] Water 82256 80841 79720 88751 85238 81930 81272 +----------+-------+-------+-------+-------+-------+--------+ 10000 99971 10000 99925 10000 10000 10000 +------------------+----------+-------+-------+-------+-------+-------+--------+

=PLUMBA'GO.= _Syn._ GRAPHITE, BLACK-LEAD. One of the native forms of carbon. It contains from 95 to 100% of pure carbon; has a metallic l.u.s.tre, and conducts electricity nearly as well as the metals. It was formerly regarded as a carbide of iron, but the iron generally found is now known to be merely in a state of mixture. There are two distinct varieties of graphite--crystallised or foliated graphite, obtained chiefly from Ceylon; and amorphous graphite (the ordinary plumbago or black-lead), largely imported to this country from Germany. The Borrowdale mine in c.u.mberland, from which the finest black-lead was formerly derived, is now nearly exhausted. The foliated graphite of Ceylon and other parts is the princ.i.p.al material employed for making plumbago crucibles and other fire-resisting goods. The amorphous graphite is used for making black-lead pencils, polishing powder for stoves and grates ('l.u.s.tre,' 'servants'

friend,' &c.), and to diminish friction in heavy machinery (anti-friction powder). Its powder is also used to give conducting surfaces to articles on which it is desired to deposit copper by the electrotype. In medicine plumbago has been used with apparent advantage in herpes and several chronic skin diseases--externally, as an ointment made with four times its weight of lard; and internally, made into pills.

_Purification._ For medical and chemical use graphite may be treated as follows:--

1. (Dumas and Stas.) Heat it to redness with caustic pota.s.sa, in a covered crucible, then wash it well with water, boil it in nitric acid and in aqua regia, again wash it with water, dry it, and expose it at a white heat to a stream of dry chlorine gas; lastly, wash it with water, and again heat it to dull redness. In a.n.a.lysis.

2. (Ph. Bor.) Pure native plumbago, 1 lb., is boiled in water for 1 hour, then drained, and digested for 24 hours in a mixture of water, 8 oz.; nitric acid and hydrochloric acid, of each 2 oz.; it is, lastly, well washed with water, and dried.

3. (Brodie's patent.) This process is only applicable to the hard varieties of graphite, as that of Ceylon. It consists in introducing coa.r.s.ely powdered graphite, previously mixed with 1/14th of its weight of chlorate of pota.s.sa, into 2 parts of concentrated sulphuric acid, which is heated in a water bath until the evolution of acid fumes ceases. The acid is then removed by water, and the graphite dried. Thus prepared, this substance, when heated to a temperature approaching a red heat, swells up to a voluminous ma.s.s of finely divided graphite. This powder, which is quite free from grit, may be afterwards consolidated by pressure, and used for making pencils or other purposes.

=PLUM'BIC ACID.= Binoxide of lead occasionally receives this name on account of its combining with some of the bases to form compounds which have been called plumbates.

=PLUM'b.u.m COR'NEUM.= See LEAD, CHLORIDE OF.

=PLUM'OSE AL'UM.= The old name of the silky amianthine crystals of the double sulphate of aluminum and iron occasionally found on alum slate.

Asbestos has also been so called.

=PLUNKET'S CANCER REMEDY.= See CAUSTIC, PLUNKET'S.

=PNEUMONIA.= Inflammation of the substance of the lungs. When the inflammation extends to the pleura, or covering of the lungs, the disease is distinguished as PLEURO-PNEUMONIA. By most pathologists pneumonia is described under the three general heads of--(1) Croupous pneumonia, (2) catarrhal pneumonia, (3) chronic pneumonia, each of which have, by some medical writers, been subdivided into other forms and varieties.

1. ACUTE CROUPOUS PNEUMONIA. This first description of pneumonia is most common amongst persons of from twenty to thirty years of age, although no age escapes it, and it is generally very severe in character when it attacks the very young or old. It prevails more amongst men than women, since the former, from their more frequent exposure to the weather and to changes of temperature, run greater risk of being overtaken by a very fertile cause of croupal pneumonia, viz. a sudden chill when the body is unusually heated.

It frequently seizes those suffering from chronic or acute disorders, as well as those who are intemperate and drunken. It often a.s.sails patients suffering from contagious and acute maladies, such as measles, smallpox, pyaemia, puerperal fever, typhus, and as appears from the accounts of the recent outbreak of Astrakan plague in that disease also. It likewise frequently prevails amongst the poor and badly fed living in the overcrowded quarters of large towns and cities.

The following are the princ.i.p.al symptoms of acute croupous pneumonia, given by Dr Roberts:[113]--

[Footnote 113: 'Handbook of the Theory and Practice of Medicine,' by F. J.

Roberts, M.D., &c. Lewis, 1873.]

"In some cases there are premonitory signs of general indisposition for a short time. In primary, or unmixed pneumonia, the attack sets in usually very suddenly, the invasion being attended with a _single, severe, more or less prolonged rigor_. There may be great prostration with fever; vomiting or nervous symptoms, viz. headache, delirium, restless stupor, or, in children, convulsions. The special symptoms are _local_ and _general_.

"_Local symptoms._--Pain in the side is usually present, commonly stabbing or piercing, increased by a deep breath. Difficulty of breathing. Cough also commences speedily; it does not come on in violent paroxysms, but is short and hacking and difficult to repress. Soon expectoration occurs, the expectorated matter presenting peculiar characters. It is scarcely at all frothy but extremely viscid and adhesive, and the vessel which contains it may often be overturned without its escaping. The expectorated matter has a rusty colour or presents various tints of red, from admixture of blood, and as the case progresses, changes of colour are observed through shades of yellow, until finally they become merely like the expectoration of bronchitis. In some cases of croupal pneumonia pain and other symptoms are sometimes very slight or absent, and the expectoration may be merely like that in bronchitis, absent, or in low cases present the appearance of a dark, offensive, thin fluid, resembling liquorice or prune juice.

"_General symptoms._--These may be summed up generally as severe fever with great depression and prostration. The skin is hot, dry, and burning.

The temperature rises with great rapidity to 102, 103, 105, or sometimes higher. It has been known to reach 107 in cases which recovered, and in fatal cases it has attained to 1094. In a large number of instances it does not exceed 104. There is usually considerable flushing of the cheeks. The pulse ranges generally from 90 to 120, or may be much above this."

In the majority of cases this variety of pneumonia has a favorable termination, but however slight the form in which it shows itself, or the mildness of its attack, the properly qualified pract.i.tioner should be called in to combat it. We have described the nature and cause of the disease and given the course to be followed in treating it, for the benefit only of the emigrant and others similarly situated. The above comments are meant to apply to the other descriptions of pneumonia, which will be adverted to in the course of the present article.