285 



AMMONIUM. 



AMOMUM. 



2S6 



The Ammonites were uncircumcised (Jer. ix. 26), and worshipped 

 Molech or Milcom, and their idolatry was, by the Ammonitish wives 

 of Solomon, introduced among the Israelites. (1 Kings xi. 7, 33 ; 2 

 Kings xxiii. 13.) 



Of their kings, we know only Nahash and Hanun, in the time of 

 David ; and Baalis, contemporary with Nebuchadnezzar. (Jer. xl.) 



AMMONIUM. (NH,). The hypothetical compound radical of the salts 

 of ammonia. When ammoniacal gas unites with acids to form salts, 

 the latter are regarded as no longer containing NH 3 , but as compounds 

 of the radical NH,. Thus, when ammoniacal gas unites with hydro- 

 chloric acid, the salt chloride of ammonium is formed, containing the 

 radical in question united with chlorine. 



NH 3 + HC1 = (NH,) a. 



In like manner, when ammoniacal gas unites with a hydrated oxyacid, 

 it is supposed that the water of hydration of the acid coalesces with 

 the body, NH.,, so as to form oxide of ammonium, which then unites 

 with the acid to form a salt of ammonia. Thus, ammouiacal gas and 

 hydrated nitric acid form nitrate of ammonia, NH 3 + HO, N0 5 = 

 (NH,)0, NO S . In the salts of ammonia, therefore, the radical ammonia 

 takes the place of the metal in ordinary metallic salts ; and nitrate of 

 ammonia, and chloride of ammonium, for instance, thus become 

 analogous in their constitution to nitrate of potash and chloride of 

 jiotassiimi. 



Nitrate of potash 

 Nitrate of ammonia 

 Chloride of potassium 

 Chloride of ammonium 



KO, NO S 

 (NH,)0, N0 5 

 KC1 

 {NII.lCl 



This view, first suggested by Ampere, and subsequently applied by 

 Berzelius, is frequently termed the ammonium ttteory. Ammonium has 

 never been obtained in a separate state, and is probably incapable of 

 existing free from any other body. Reasoning from the analogy of its 

 compounds with those of the metals, it has by some been regarded as a 

 true metal ; but although its compound with mercury [AMALGAM] 

 lends some support to this notion, yet the non-metallic character of 

 other isolated radicals renders the metallic attributes of ammonium 

 highly improbable. 



Acetate of Ammonia (NH,0, C,H S 0,). This salt is prepared by 

 adding sesquicarbonate of ammonia to dilute acetic acid. Owing to the 

 superior affinity of the acetic acid for ammonia, the carbonic acid is 

 expelled from it with effervescence, and a colourless solution remains, 

 which contains neutral acetate of ammonia, but which, when concen- 

 trated and placed under the exhausted receiver of an air-pump over 

 sulphuric acid, loses ammonia and yields transparent prismatic crystals, 

 which are very deliquescent, and consist of an acid salt. The neutral 

 salt may be obtained in the crystalline form by saturating glacial acetic 

 acid with ammoniacal gas. It is white, and very soluble in water and 

 in alcohol. 



Acetate of ammonia is directed to be prepared in the ' London Phar- 

 macopocia,' and kept in solution under the name of Liquor A /// 

 Aeetatli. It is <ised externally as a refrigerant, and internally as a 

 diaphoretic, and is commonly known by the name of Spirit of JUinde- 



Oxalate of Ammonia (C,O S , 2NH,0, + 2aq. ). This salt is prepared 

 l>y adding sesquicarbonate of ammonia to a solution of oxalic acid, until 

 it is saturated. The solution by evaporation yields small prismatic 

 crystals; these are devoid of smell, have a bitter, saline taste, and 

 dissolve readily in water. By dry distillation they yield oxamide. 

 Oxalate of ammonia is used as a test of the presence of lime, and to 

 precipitate it from solution in chemical analyses. 



AMMOXITM. CHLORIDE OF. (NH.C1.)' This salt has been 

 long known, and extensively used, under the name of Hal Ammoniac. 

 The substance from which it was first procured, was the soot of 

 camel's dung. It is now largely manufactured hi Europe, by com- 

 bining hydrochloric acid, either directly or indirectly, with the 

 ammonia obtained from the decomposition of animal matter, but prin- 

 cipally from the liquor obtained during the preparation of coal-gas. 

 This impure ammoniacal liquor is at once saturated with hydro- 

 chloric acid, and evaporated to crystallisation. The crystals are then 

 sublimed. 



Chloride of ammonium, an obtained by sublimation, is an amorphous, 

 translucent, colourless salt ; but when separated'from water by crystal- 

 lisation, its form is cubic. It has a sharp, saline taste, but no smell, 

 and dissolves readily in water ; exposure to a dry air produces no 

 change in it ; by heat, it volatilises without decomposition. Lime and 

 the fixed alkalies decompose it, evolving ammoniacal gas ; and sulphuric 

 acid expels hydrochloric acid gas. It is composed of equal volumes of 

 hydrochloric acid gas and ammoniacal gas, as may be shown by the 

 ferfect condensation of these proportions in a jar over mercury ; or by 

 weight, of 



One atom of hydrochloric acid . . 36'5 

 One atom of ammonia . .17.0 



Atomic weight 



53-5 



This salt is much employed in the tinning of iron, copper, and brass, 

 and in agriculture. It is generally used for preparing ammoniacal 



gas, and the sesquicarbonate of ammonia, in the modes already 

 described. 



AMMONIUM AMALGAM. [AMALGAM.] 



AMMONIUM, IODIDE OF (NH.I). Prepared by saturating a 

 solution of hydriodic acid with ammonia, and then evaporating until 

 the salt crystallises. Iodide of ammonium crystallises in cubes which 

 are deliquescent, and is slowly decomposed on exposure to air and light. 

 It ought, therefore, to be preserved in well stopped and opaque bottles. 

 It is easily soluble in water, and also in alcohol and ether. The latter 

 property has led to its extensive use in photography for iodising 

 collodion. Iodine is very soluble in an aqueous solution of iodide of 

 ammonium. 



A'MNESTY is a word derived from the Greek a^vrimia, amnestia, 

 which, literally, signifies nothing more than non-remembrance. The 

 word amnatia is not used by the earlier Greek writers ; but the tiling 

 intended by it was expressed by the verbal form (/ufj /ut)(riKajce?j'). The 

 word fyinjo-Tia occurs in Plutarch and Herodian. Some critics suppose 

 that Cicero (' Philipp.' i. 1) alludes to his having used the word ; but 

 he may have expressed the thing without using the word amnestia. It 

 occurs in the fife of Aurelian by Vopiscus (c. 39), according to some 

 editions in the Latin form, but it is possible that Vopiscus wrote the 

 word in Greek characters, and it is doubtful whether the word was 

 ever incorporated into the Latin Language. Nepos, in his life of 

 Thrasybulus (c. 3), expresses the notion of an act of Amnesty by the 

 words " lex oblivionis," and it is clear from a passage in Valerius 

 Maximus (iv. 1), that the word was not adopted into the Latin 

 language when Valerius wrote, whatever that time may be. 



The notion of an amnesty among the Greeks was a declaration of the 

 person or persons who had newly acquired or recovered the sovereign 

 power in a state, by which they pardoned all persons who composed, 

 supported, or obeyed the government which had been just overthrown. 

 A declaration of this kind may be either absolute and universal, 

 or it may except certain persons specifically named, or certain classes 

 of persons generally described. Thus in Athens, when Thrasybulus 

 had destroyed the oligarchy of the Thirty Tyrants, and had restored 

 the democratical form of government, an exceptive amnesty of past 

 1 ill ticul offences was declared, from the operation of which the Thirty 

 themselves, and some few persons who had acted in the most invidious 

 offices under them, were excluded. (Xenophon, ' Hellen.' ii, 4, 38 ; 

 Isocrates, ' Against CaUimachus,' c. 1.). So when Bonaparte returned 

 from Elba in 1815, he published an amnesty, from which he excluded 

 thirteen persons, whom he named in a decree published at Lyon. 

 The act of indemnity, passed upon the restoration of Charles II., 

 by which the persons actually concerned in the execution of his 

 father were excluded from the benefit of the royal and parliamentary 

 pardon, is an instance of an amnesty. from which a class of persons 

 were excepted by a general description and not by name. Of a like 

 nature was the law passed by the French Chambers in January, 1810, 

 upon the return of Louis XVIII. to the throne of France after the 

 victory at Waterloo, which offered a complete amnesty to " all persons 

 who had directly or indirectly taken part in the rebellion and usurpa- 

 tion of Napoleon Bonaparte," with the exception of certain persons, 

 whose names had been previously mentioned in a royal ordinance as 

 the most active partisans of the usurper. It was objected to this 

 French law of amnesty, that it did not point out with sufficient per- 

 spicuity the individuals who were to be excepted from its operation. 

 Instead of confining itself to naming the offenders, it excepted whole 

 classes of offences, by which means a degree of uncertainty and con- 

 fusion was occasioned, which much retarded the peaceable settlement 

 of the nation. " In consequence of this course," says M. de Chateau- 

 briand in a pamphlet published soon after the event, " punishment and 

 fear have been permitted to hover over France ; wounds have been 

 kept open, passions exasperated, and recollections of enmity awakened." 

 The act of indemnity, passed at the accession of Charles II., was not 

 liable to this objection, by the distinctness of which, as Dr. Johnson 

 said, " the flutter of innumerable bosoms was stilled," and a state of 

 public feeling promoted, extremely favourable to the authority and 

 quiet government of the restored prince. 



AMO'MUM Medical Propertie of this and allied Genera. This 

 comprehensive heading is adopted to include many aromatic stimulants, 

 such as cardamoms, grains of paradise, &c., which are obtained from 

 several plants related to amomum. German pharmacopolists even 

 term Pimento berries, or Jamaica allspice, semen amomi ; but this in 

 never BO called in Great Britain. Much obscurity hung over the 

 history of the true cardamoms, which recent investigations have 

 removed ; and as Dr. Pereira has treated the whole subject at great 

 length in his ' Materia Mcdica,' his statements are chiefly followed 

 here. 



The true, officinal, or Malabar cardamoms are procured from the 

 elettaria cardamomum (Rheede, ' Hortus Malabaricus,' vol. ix.), White ; 

 the botanical characters of which were described by Dr. Maton 

 ('Trans. Linn. Soc.' x. p. 254). The Edinburgh College term it 

 rertealmia, (Rose.) ; the London, alfinia cardamomum (Roxb.). It 

 occurs in the mountainous parts of Malabar, and is also cultivated. 

 The cardamoms of the Wynaad, which are the most esteemed and 

 bring the highest price, are cultivated. The fruit is the part collected, 

 but the seed alone is used. The seed-vessel or husk is altogether 

 devoid of aroma or pungency ; but the seeds should never be taken out 



