GAS 



are introduced the leaves of bear's-foot pounded ; the opening 

 is tlien fewn with two or three ftiches, and thus will be pro- 

 duced a running which will cure the difeafe ; or a common 

 rowel will anfwer the purpofe. 



GARRARD. Add— It contains 8926 inhabitants, of 

 whom, in 18 10, 2000 were flaves. 



GARSTANG, 1. 3, r. 178 and 790. 



G A RUGA, in Botany, a very barbarous Indian name. 

 — Roxb. Corom. v. 3. 5. Ait. Hort. Kew. v. 3. 37. — 

 Clafs and order, Decandria Motwgynia. Nat. Ord. Melia, 

 Juff. 



Eff. Ch. CalyK bell-fliaped, five-cleft, bearing the 

 ftamens and the five equal petals. Stigma five-lobed. 

 Drupa with feveral nuts. 



I . G. phuiata. Roxb. t. 208. — A tree found on the 

 mountains of India. Leaflets ferrated. Fhiuers panicled, 

 yellow. Fruit auilere, ufed for pickling. Wood foft. 



GAS, col. 2, 1. 25, after atmofphere, add — will be 

 found under Air, Atmosphere, &c. ; dele llated under the- 

 head of Pxeumatics. 



Gas, in Chemiflry. Great revolutions have taken place 

 in t-he chemiftry of the gafes fince this article was written 

 for the Cyclopaedia. Not only have their number been 

 increafed, but the laws of their combination, expanfion by 

 heat, &c. have been further inveiligated, and in many 

 inilances found very different from tliofe ftated under the 

 above article. Several of thefe particulars have been already 

 given under the article A-ToyilcTheory, a few others remain 

 to be mentioned here. The following table from Dr. Thom- 

 fon includes the gafes at prefent known. 



1. Simple gafes. Oxygen, chlorine, iodine vapour, hydro- 



gen, azote, fulphur. 



2. Compound gafes. a. Simple gafes combined. Hydriodic 



acid, protoxj'd of chlorine, prot- 

 oxyd of azote. Muriatic acid, 

 deutoxyd of azote, fteam, am- 

 monia. 

 h Oxygen and a folid bafe. Sulphu- 

 ric acid, fulphureous acid. Car- 

 bonic oxyd, carbonic acid. 



c. Hydrogen and a folid bafe. Cya- 



nogen, fulphuretted h)'drogen, 

 defiant gas, carburetted hydi-o- 

 gen, hydroguret of phofphorus, 

 bihydroguret of phofphorus. 



d. Fluorine, chlorine, and cyanogen 



with a bafe. Fluoboric acid, 

 chlorocyanic acid, hydrocyanic 

 acid, chlorocarbonic acid. 



e. Two folid bafes. Sulphuret of 



carbon. 



f. Triple or quadruple compounds. 



Hydriodic ether, chloric ether, 

 fulphuric ether, muriatic ether, 

 alcohol, oil of turpentine. 

 Combination of Gafes with one another. — The important law 

 firft obferved by Gay Luffac refpefting the combination 

 of gafeous bodies, and alluded to in our original article, is 

 now, we believe, nearly univerfally admitted. This law is, 

 that gafeous bodies always unite with reference to their 

 volumes ; that is to fay, that either equal volumes of dif- 

 ferent gafes combine together, or one volume of the one, 

 with two, three, or more of the other, and not with any 

 intermediate proportion ; and further, that when a gafeous 

 refult is obtained by fuch union, the volume of this is either 

 equal to the united volumes of the two gafes, or to half, 



GAS 



one-fourth, or fome other fubmultiple of the original 

 volumes. 



The combinations of gafes with one another have been 

 arranged by Dr. Thomfon under the following heads. 



1 . Gafes that unite by mere mixture, fuch are : Oxygen 



with nitrous gas, forming nitrous or nitric acid. 



Ammonia with vapour, forming liquid ammonia 



vv'ith muriatic acid, forming muriate of ammonia 



with fluoboric acid, forming fluoborate of ammonia 



with fluofilicic^acid, forming flluofdicate of ammonia 



with carbonic acid, forming carbonate of ammonia — 

 with fulphureous acid, forming fulphite of ammonia — 

 with fulphuretted hydrogen, forming hydrofulphuret 

 of ammonia. 



2. Gafes that may be mixed without any ilriking com- 



bination, though they are capable of uniting in certain 

 circumftances, fuch are : Oxygen •n-ith hydrogen, form- 

 ing' water — with carbonic oxyd, forming carbonic 

 acid — with azote, forming nitric acid — with chlorine, 

 - forming chloric acid — with fulphureous acid, forming 

 fulphuric acid — with nitrous oxyd, forming nitric acid. 

 Hydrogen with chlorine, forming muriatic acid — with 

 iodine, forming hydriodic acid — with cyanogen, 

 forming hydrocyanic acid. Chlorine with carbonic 

 oxyd, forming chloro-carbonic acid. 



3. Gafes which mutually decompofe each other when mixed 



together, fuch are : Oxygen with phofphuretted hydro- 

 gen. Chlorine with ammonia — with phofphuretted hy- 

 drogen — with carburetted hydrogen — with oiefiant gas 

 — with fulphuretted hydrogen — with nitrous gas. Sul- 

 phuretted hydrogen with nitrous gas — with fulphureous 

 acid. 



4. Gafes which mix without fpontaneous decompofition, but 



which may be made to decompofe each other in parti- 

 cular circumftances, as on the approach of an ignited 

 body, when electric explofions are pafTed through them, 

 &c. Thefe are more numerous then the preceding, 

 and are as follow : Oxygen with fulphuretted hydrogen 

 — with carburetted hydrogen — oiefiant gas — vapour of 

 ether — vapour of alcohol. Nitrous oxyd with hydrogen — 

 with phofphuretted hydrogen — fulphuretted hydrogen 

 — carbonic oxyd — carburetted hydrogen — oiefiant gas 

 — vapour of ether — vapour of alcohol — fulphureous acid. 

 Nitric acid with hydrogen, and probably all the pre- 

 ceding combuftible gafes and vapours — with fulphureous 

 acid. Nitrous gas with hydrogen — with fulphureous 

 acid. Hydrogen with fulphureous acid — with carbonic 

 acid. Vapour of water with carburetted hydrogen — 

 with oiefiant gas. 

 Combination of Gafes ivitb Liquids. Gafes may be confidered 

 with reference to their combination with water and with 

 other fluids. With refpeft to water, by far the moft im- 

 portant of all fluids, gafes may be divided into two cirifles ; 

 thofe that are abforbed in a fmall proportion, and thofe that 

 are abforbed in a great. Almoft all gafes belong to the firfl 

 clafs. In the following lift of this clafs, the gafes are arranged 

 in the order of their abforption, beginning with the leaft 

 abforbable : azotic gas — hydrogen gas — arfenical hydrogen 

 — carburetted hydrogen — carbonic oxyd — phofphuretted 

 hydrogen — oxygen gas — nitrous gas — oiefiant gas — nitrous 

 oxyd — carbonic acid — fulphuretted hydrogen. 



The following laws feem to be pretty well eftabli.'hed 

 refpeding the abforption of gafes by water. 



I. When the preffure, temperature, and purity of the 

 water, are the fame, water abforbs a determinate quantity of 



every individual gas. 



2. Water 



