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he suilla to the common Standard, is previousty directed. Isthe whole charge of acid, Water, and Salt be introduced into the retori, the sirsi subsequent application of heat delaches muriatic acid gas Without a sussicient quantity of water tocondense it, and a portion in this Way Passes to waste. Byintroducing so me of the water into the receiver this gas is condensed, and the produci is in the fame proportion Stronger. For the condensation of the Whole muriatic acid gas a certain quantity of water is necessary, and, in addition to that whicli is here directed to be used, the quantity also containedin the crystals of the sali is to be talien into the account ;for these crystals are only to be dried, not decrepitaled. The purest muriate of soda will be Dund to be that whicli is call-ed in trade by the name of bes sali. A tubulated receiverwith an attached botile containing the water, or any modification of Wo ulla's apparatus, may be u Sed at the pleasure orconvenience of the operator, but sucti is not directed in ilin
sussicient, is care be talaen not to lute them clos eiu untii ali thea tmospheric air be first expelled. By the previ ous dilutionos the sulphuric acid the Charge Will be hept in a quiescent state untii the application of heat be made, and thus timewill be given to the operator for the adaptation of the r ceiver. The addition of the sali to the acid is also os importarice, because it prevenis the chance of any subsequent accident to the retort. The charge should not occupy morethan half the body of the retori, and as it is os consequenceto preserve the Vesset, it may be proper to add, that this may perhaps best be done When iis contenis have cooled to abo ut 2 2', by pouring in suffcient Water at the Same temporatureto sill it. The muriatic acid gas ora iis absorption by Water, gives out considerable heat, and raises iis temperature. In
the fame proportion also is iis poWer os condensing the gas
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diminished, so that it is necessary to keep the receiver cooled during the process. The residue is sulphate of soda, mittia superabundance of sulphuric acid, and is farther to be prepared accor ling to the directions given for that sali. Thisacid is colourless, or more commonly haS a Pale yello tinge. It has been supposed by sonae, that is the salt was driod theacid would uniformly be colouri ess; this however is not thecase, as the colour inVariably aris es Dom iron. Is it contain any sulphuric acid it may be discovered by muriate of barytes, and purifled thereisom, is such purification hethought necessary, by a second distillation froni a smaliquantity of muriate of soda. pluriatic acid gas, extricat ed Dom the addition os sulphuricacid to common sali in iis form os gas, was the frst of the series employed by Guyton de Morveaia, for the purpose of destroying contagious matter in an atmosphere infected wittiit, but whicli has the great inconvenience of irritating the lungs of those who inhale it in any degree os concentration. Is with the muriate of soda about one half iis weight ofhlach oxyd of manganese be miXed in a tubulated retori, so that the addition of the sulphuric acid may be gradually made, thepeculiar elementary substance, noW called by sir Η. Davychlorine, by Lavolsier o muriatis acid gas, and by iis dis- coverer Scheele, in III4, dephlogisticaled marine acid willhe obtain ed. Or, sor the immediate extrication of the samegas, three paris of common Salt by Weight, one of blach oxydos manganese, and tWo os strong Sulphuric acid may be mix edtogether. The gas passed through Water may be united With it under moderate pressure in about double the bulla thereos, when iis taste mill be acrid and iis smeli disagree- able. Ιt has been said to be advantageousty ven in Onanche maligna, in the proportion of M. to Oct . s. of Water,
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subcarbonate of the fame. From Dr. Rollo's experiments at Woolwicli, this seems to be the most POWerful of the gassessor the destruction os contagious matter in the atmosphere; but it ought to be most cautiousty USed Under any Circumstance, Where there is a chance of iis being inspired : I have nevertheless occasionalty employed it in Sich rooms, without the inconvenience Whicli might be expected.
Aeidum nitrosum, P. L. I 787. Spiritus Nitri Glauberi. Aqua fortis, P. L. II 15. Aqua fortis simplex & duplex, P. L.
Mix them in a glass retori, then distit theni trio ac id in a sand bath, untii a reii Vapourarises: lastly, having ad ded to the acid si si distilled an ounce more os dry nitrate os potass, distit the nitrio acid again in a similar
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os a lum p os lime sto ne immersed therein
One OUn CC. The proportion os sulphuric acid here gi ven is much largerthan what has been usualty employed, though authors haVehereto re varie d much in the proportions they have directed, and Frederic Ho an used equat paris of the sali and acid. The incretae has been made chiessy with a view to obtain thenitric acid as Dee as possibie Dom nitrous gas ; and when this arises, whicli is discoverable by the red colour it imparis to the acid, the process is to be stopped. The quantity of acidthus obtained is greater in iis value than wbere half the weight only of sulphuric acid is used ; iis colour is also much pater, and it is there re better nitric acid, but it may perhapsbe considered as tess pure, because it is more lihely to contain sulphuric acid; and on this account a seconii distillationfrom a fresti portion os nitre is directed. The nitric acid is commoraly prepared by heating the coloured acid untii the redianaes c ea se to ariSe and it be comes colourless ; but in sucha Process not Only nitrous gas but a large proportion of the acid it self passes io Waste. Is any sulphuric acid be present, nitrate of barytes will discover it, and is added in suffcient quantity, Will also remove it, as Will the nitrate os silver any muriatic acid ; but aster the second distillation sucti an impurity is not to be expected. A tubulat ed receiver and attached vesset, hept cold by immersion in Water Or ice, orWoulla's apparatus, may be used. It is a further a luantage of the present process, that the remaining mass is easilyremovable by hot water frona the retori, by the ready solubility of the acidulous sulphate os potass, Whicli is formed. Nitric acid, is pure, is transparent and almost colourless,
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65hut it is more commonly Orange-cOlOIared, Dom ille presenceos nitrous gas. In the former state of these it emits white fumos, in the lalter orange-coloured ones: it tinges the cuticleos a permanent yello colour, and is sussiciently long applied corrodes the s Ein iiself as a caustic. The specific gravity is stat ed to be I, 50O, whicli is loWer than some aut hors have given it. The Edinburgh Pharmacopoeia mahes it I, 55O, and Μr. Rirwan at 6O', I, 5543, and at this he considers IO0pis . to contain 73, 54 of real acid Dee frona water. The re agon for the adoption of these proportions fornitric acid, is expressed in the folloWing repori made to the College.
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Was a fre-place, and, near it in the other, a smali si pane twindow and a door: his friends Dom without acted as most attentive nurses, and the fumigation of the room by nitricaci I gas Was carefulty attended to; a number of them relievelothers through successive nighis and days, and none of themor of his medicat attendanis, Suffered by the disease.
Acidum nitrosum dilutum, P. L. I 87.
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Acidum DPriolicum ritulum, P. L. I 87. Spiritus vitrioli tenuis, P. L. 1745.
Add the Acid to the Water gradu ally, and
This diluted acid is stronger than the former nearly as sto 4, but it is more rea lily made by mixture than weight, and iis proportionate dose is eastly administered, especiallyas minute attention thereio is not of any great practical importance. The diluted acids are intended for the purposeos internat administration, and more convenient and certain division of the dose. One ounce of sulphuric acid, bymeasure, is equat to about l. drachms by weight. One fluid-ounce of this diluted acid will saturate about 1O7 grs. of dried subcarbonate of soda; and it is in strength to the admixturoos one ounce acid, by Weight, and eight water used in theformer Ρharmacopoeia, nearly as 3 to 2, and it containsrather more than δε of acid by meastare. Is sulphuric acidbe diluted with an equat measure of Water, and cooled to the temperatUre, another equat measure of Water raised it about 2l', and a third added in the fame manner about 7'.
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Ammonia praeparata, Sal cornu cervi, P. L. II 8 . Sal volatilis salis ammoniaci, P. L. 1745. Sal volatilis, P. L. I 720.
In this process a doubie decomposition talaes place, and tWO neW compoUndS, Carbonate os ammonia and muriate oflime, are formed. To effect this, a high temperature, as here expresSed, becomes requisite, and the employment also os asultable additional apparatus hept at a low one for the colle tion and condensation of the sublimed sali; for which lalter Purp0se a Wide mouthed glass retori and receiver Will ansWer,
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69care being taken that it is never completely closed. The proportions of the miXtUre are noW altered, and that of the prepared challa is reduced Dom tWO poUnds, to one potindand a half; which is stili more than is absolutely necessarysor the decomposition of the muriate. I he residue, however, is of litile value, and the superabundant quantity is onthe right fide for the security of the preparation. Davystates the relative proportions os constituent paris of the compounds of carbonic acid and ammonia to vary accord- ing to the temperature employed ; in loN ones there is more acid and water, in high ones more aikali. Bergmangives the proportions as carbonic acid 45, ammonia q3, Water I 2; and prepared according to the present directions, it is, in faci, a subcarbonate os ammonia, whicli it is noW named ;when sublimed, it forms a calae of striated crystalline appea ance, smelling Strongly of ammonia; When heated it melis Dom the quantity of Water contained, becomes dry as this eVaporates, and at last sublimes entirely may unaltered. TWo paris of cold water dissolve one of this sali, bolling Water
dissolves more than iis Weight. In the former Pharmacopoeia, the fame sali Was also prepared by distillation Dom bones, purifled by repeated sublimation Dom challa, and kept under the name of Ses Cornu Cervi. The name Ammonia, used to distinguisti this athali, Was originalty derived Dom the circumstance of one of iis salts being then obtained in large quantities from theneighbourhood of the temple of Iupiter Ammon in Lybia
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Aquae ammoniae purae, P. L. 17ST.
Tu ke of Muriate of Ammonia, eight
It must be carefulty remembered, that Liquor ammonia Ofthe present Pharmacopoeia corresponds With Aqua ammonia surae, and not With Aqua ammoniis of the former. The limeshould be Dee Bom carbonic acid, so that the liberaled ammonia may be pure. The process is altered Dom that of the Iast edition, which was inconvenient Dom iis strength, and certainly less applicabie, theresore, to internat administration.