AIDE-DE-CAMP. 



AIR 



M 



If aperients are necessary, they should Iw warm and aromatic, and 

 given .luring the intermuston, so that their operation may be over 

 before the accession of the paroxysm. Organic disease is occasionally 

 produced by ague. The organ* that are mo*t liable to be diseased are 

 the liver and the iipleen ; thene become enlarged and hardened, 

 itcirrhous, a* it in technically termed. The tumour* occanionally press 

 upon the great vein* of the liver, and prevent the blood from pausing 

 freely from the alidomiual vim-era, and produce dropsy ; they aim press 

 upon the duct* that cam- the l.l.xl from the liver into the duodenum, 

 or the small intestine* which receive it ; it may, therefore, be taken up 

 by the absorbent* and carried into the blood, diffused over the system, 

 and BO produce jaundice. In the same way diarrhoea may be 

 produced. 



Change of situation is a most powerful remedy ; 1st, because it may 

 remove the patient out of the sphere of the (wison that produces the 

 malady : I'n.ih . Iwcause this i one of the disease* in which mere 

 change of air is beneficial. 



This disease is peculiarly apt to return. Relapse is brought on by 

 \ .iv slight causes ; a very small dose of the poison will renew it 



It is probable that errors in diet, or con>tipati..u will also do it. It 

 U certain that cold, and that the east wind will do so ; but it is pro- 

 It,!, 1,. that ill the cold and moist air, and in the east wind, there is 

 dill'nsed wniie of the malaria. The patient should not go out in damp 

 or cold weather, or during the east wind. 



In protracted and obstinate cases which do not yield readily to 

 quinine, arsenic is a very powerful remedy, and its efficiency is 

 increased by it* combination with opium or quinine. The proper dose 

 of the arsenic U from two or three to ten drops of the liquor arseni- 

 calis three times a day. This remedy should always be given soon 

 after a meal ; for if taken when the stomach is empty, it is apt to 

 produce pain and vomiting. The O]>eration of the remedy should also 

 be carefully watched day by day ; for, like other mineral i>oisons, it is 

 apt to lie latent in the system for a considerable time, producing no 

 apparent effect, ami then suddenly to produce violent symptoms. 



AIDE-DE-CAMP, n French term, denoting a military officer usually 

 of the rank of captain, one or more of whom is attached to every 

 general officer, and conveys all his orders to the different parts of his 

 command. A field-marshal is entitled to four, a lieutenant-general to 

 tw.>. and a major-general to one. The monarch appoints as many 

 aides-de-camp as he pleases, and this situation confers the rank of 

 . ol..n..l. At the end of 1858, the number of aides-de-camp to the 

 queen was thirty-five. There were also eleven naval aides-de-camp to 

 the queen, one of whom, of the rank of admiral, is styled first and 

 principal aide-de-camp, and has a salary of 365/. per annum ; and ten 

 others, of the rank of captain, have 182/. 11. per annum. There are 

 also two aides-de-camp appointed by the queen from the officers of the 

 Koyal Marines, whose salary is the same as that of the naval aides- 

 de-camp. 



AII'S tfrom the French -I/V>.. which in the sense of a tax is used 

 only ill the ]iliir.il numlier). Under the feudal system, aids were claims 

 of tin- lord u|n the vassal, not o directly connected with the tenure 

 of land as reliefs, fines, and escheat*. The nature of these claims is 

 indicated by the term : they were rather extraordinary contributions 

 than demands due according to the strict feudal system, though they 

 were founded on the relation of lord and vassal. These aids varied 

 according to local custom, and became in course of time oppressive 

 exactions. The aids which are mentioned in the 'Grand Costumier' of 

 Normandy for knighting the lord's eldest son, for marrying his eldest 

 daughter, and for ransoming the lord from captivity, were in use in 

 England, having been prolmbly introduced by the N it other 



HiiU were also established by usage or the exactions of the lords, for by 

 Magna Charta, c. 12, it is provided that the king shall take no aids, 

 except the three above mentioned, without the consent of Parliament, 

 and that the inferior lords shall not take any other aids. 



The amount of the two aids for knighting the lord's eldest son and 

 Hurrying his eldest daughter was limited to a certain sum by the 

 St.it lite of Westminster 1, 3 Ed. I. c. 36. The aid which wan to ransom 

 the lord when taken prisoner was of course uncertain in amount. Aids 

 for knighting the lord's son and marrying the lord's daughter are 

 .'-li-hcd by the sUt 12 Car. II. c. 24. The aid for ransoming the 

 l"id is obsolete. 



A !ii* is also a general name for the extraordinary grants which are 

 made by the House of Commons to the crown for various purposes. 

 In this sense, aid . .md (lie modern term supplies, are tire 



wine thing. The aids were in fact the origin of the modern system of 

 taxation. (Mlack-t -Coin..' vol. i. p. :ii2; vol. ii. pp. 62, 86.) 



Am-ilin is the Latin word lined by Bracton and other writers when 

 they are speaking of the feudal aids alsive enumci.itcd. The word Aiilf 

 {derived from the I,ow Ijitin .lilimln. il'u I'aiigc. ' (!|OSK. Med. et 

 Infiiii. Uitin.'i The Spanish form m/inlii (' assistance i ami tire It. .km 

 duo clearly indicate the origin of the word 'aide,' which is from 

 the jurtieipial form adjula of the 1,-itin verb ailjarnrr. 



A III. This word in derived from the Greek 4)jp and Iitin aer. 

 Though generally applied only to the material of the aim., ph.i. . il.i 

 term wan, al>otit the middle of the last century, extended to all the 

 gases, an they were successively discovered, with a distinctive name for 

 mch. Though we confine ourselves here to the properties of atmon 

 phcric air only, we give the references to the modern names of the 



Oxygen. 



principal air*, as they were then oiled, which will be found mentioned 

 in the chemical works of the hist oentuiy. 



Hcphlogisticated Air, 1 



Empyreal Air, V see 



Vital Air, j 



Phlogisticated Air we 



Nitrous Air, 



Dephlogisticatcd Ni- 1 



Irons Air, 

 Inflammable Air, 

 Fixed Air, 

 Alkaline Air, 



'xidc. 



I 'eutoxide of Nitrogen. 



- Oxide. 



Protoxide of Nitrogen. 

 Hydrogen. 

 Carbonic Acid. 

 Ammonia. 



The air which envelopes the globe is a nuckanira/ mi.iii'n of 

 those simple substances, to which chemists have given the name of 



TV .- vi/.., oxygen and nitrogen, with a very small proper 

 carbonic acid, and water in the state of vapour. The two last are con- 

 sidered as accidental ingredient*, and not constituent parts; as well on 

 account of the xmallness of their quantity, as because they <> 

 different proportions at different times. The atmosphere also contains 

 a variable but minute trace of ammonia; traces of nitric acid, and ot 

 some compound of carbon and hydrogen, and often in towns Mil 

 phuroiiK acid or sulphuretted hydrogen. 



Helen-ill),' only to the two principal ingredient*, air consists on an 

 average of 20'81 of oxygen by mean/re, and 71-19 of nitrogen in 100 

 parts; or, by wtit/ltl, of 23'01 of oxygen and 76-99 of nitrogen. 

 Whether the air be brought from an elevation of four miles abo 

 surface of the earth, or collected on the summit of the Alps, or from 

 crowded towns, or open plains, in various part* of the globe, it pre- 

 sents no sensible dill'ercm-e. with respect to it* principal const r 

 from the proportions aUive given. With respect to the weight of air, 

 100 cubic inches of dry air at mean temperature and pressure weigh 

 rather more than 31 grains, the most accurate result being pr< 

 that of Biot and Arago, viz., 31 '074 grains. Hence the weigl r 

 volume of air at 60 F. and 30 in. Bar. is only ,foth that, of an 

 bulk of water at the same temperature. Water dissolves about ^-,th 

 of its bulk of oxygen, and ^,th of nitrogen; hence rain wat. 

 melted snow contain in solution a larger proportion of oxygen than 

 exists in the atmosphere, or about one part of oxygen to two ,.t nil r o 

 gen, a circumstance of great importance to aquatic animals. The 

 carbonic acid of the air is produced at the expense of it* . 

 during the processes of respiration, combustion, fenncntati. p 

 Air that has 1 en respired contains about 3j per cent, of carbonic acid, 

 although the proportion in the atmosphere does not exceed -01 per 

 cent. Certain mineral springs and the action of subterranean heat in 

 volcanic districts upon limestone rocks beneath the surface, a i 

 sources of carbonic, acid to the air. 



The average composition of the atmosphere in England, in 100 parts 

 by volume, is as follows : 



And in 



towns 



Oxygen 



Nitrogen 



('arlinic Acid 



Aqueous Vapour 



Nitric Acid 



Ammonia 



Carhiiretted Hydrogen 



! Sulphuretted H\. 

 Sulphurous Acid . 



20-61 

 77*8 



04 

 1-40 



ll ice., 

 tr.i. . -. 



Although the constituents of the atmosphere are of vei v ditleient 

 densities, yet, in consequence of the principle .1 I' , 



uniformly mixed : one atom of oxygen is accompanied by font 

 of nitrogen, but yet so slightly held together, that the oxygen is readily 

 separated from the nitrogen when required for the purposes of anim.d 



and vegetable life or combust i and by the operation of the same 



principle, the heavy carbonic acid is distributed through tin- 

 that plant* may easily alworb it, decompose it. retain the cail 

 material for growth, and return the pure oxygen to the atmosphere. 

 Some chemist.*, notwithstanding, have considered the air to U ., 



i eomponnd of 2 atoms of nitrogen to 1 of oxygen. An ntomii 

 compound of this proportion gives a ratio of in : Mi in \olunie. which 

 is very nearly that given almve. ns deduced from experiment. M. Hcg 

 nault. however c ('hiinie.' i. 1-141. has shown that tlri.- view is hardl\ 



tenable, however remarkable II .in, idem .- may U-. 



The air is of oxygen and nitrogi-n. and not a ,/ 



fombiiiniiiiii. In what the difference consists, it is imp 

 to say : but the distinction may lie illustrated by the following experi- 

 ment, which we introduce the m..re readily, as we shall affi rwanis 

 have occasion to refer to it. If eight grains of oxygen gas and one 

 i hydrogen be confined in a glass tul- from which the air Ir.rs 

 been previously excluded, they may Iw mixed in that state, and the 



thus formed will not prevent either gas from separating from 

 the other, and combining with any third Univ. That is, the o- 

 for example, will combine as readily with any substance winch 

 great affinity for it, an if the hydrogen were not present. Hut if nu 



"(ark be passed through the tube, a new milwtan. 

 out of the oxygen and hydrogen, by some specie* of mutual connexion 



