ART 



A'BSENITE. A name given by Fourcroy 

 to the combinations formed between 

 oxide of arsenic, or arsenious acid, 

 and the earths and alkalies. Ar- 

 senite of potassa is the active in- 

 gredient in Fowler's Ague Drop, 

 and in the Liquor Potassae Arsenitis 

 of the Pharmacopoeia. 



ARTE'MIS. A genus of fossil shells, 

 found in the glacial beds of Scotland, 

 Iceland, the north of England, and 

 the Isle of Man. Recent, accord- 

 ing to Adamson, it ranges as far 

 south as Senegal, and is found, 

 according to Phillippi, in the Red 

 Sea. 



A'RTERY. (from ?)/>, and ^pew, Gr. 

 artere, Fr. arterio, It. Thus called 

 because the ancients thought that 

 only air was contained in the 

 arteries.) The arteries are strong 

 elastic canals, which convey the 

 blood from the heart to the different 

 parts of the body, and, during life, 

 are distinguished from the veins 

 by their pulsation. The original 

 trunks of the arteries are two in 

 number, and from these all the 

 other arteries are derived. 



AHTE'SIAN WELLS. Springs of water, 

 or fountains, obtained by boring 

 through strata destitute of water 

 into lower strata loaded with this 

 fluid, to sometimes great depths ; 

 thus named from its having been 

 first practised at Artois, the ancient 

 . Artesium, in France. In forming 

 an Artesian well, if the boring 

 penetrate a bed containing impure 

 water, it should be continued 

 deeper until it arrive at another 

 stratum containing pure water; 

 the bottom of the pipe being 

 plunged into this pure water, it 

 ascends within it, and is conducted 

 to the surface through whatever 

 impurities may exist in the supe- 

 rior strata. The impure water, 

 through which the boring may pass 

 in its descent, being excluded by 

 the pipe from mixing with the 

 pure water ascending from below. 



The height to which these springs 

 will rise above the surface must 

 depend on the quantum of hydros- 

 tatic pressure from below ; this is 

 sometimes very great. The water 

 of an Artesian well in Roussillon 

 rises from thirty to fifty feet above 

 the surface. At Perpignan and 

 Tours, M. Arago states that the 

 water rushes up with such extreme 

 force as violently to eject a cannon 

 ball placed in the pipe. An eco- 

 nomical and easy method of sinking 

 Artesian wells has recently been 

 practised. Instead of the tardy 

 and costly process of boring with a 

 number of iron rods screwed to 

 each other, one heavy bar of cast 

 iron, about six feet long, and four 

 inches in diameter, armed at its 

 lower end with a cutting chisel, 

 and surrounded by a hollow cham- 

 ber, to receive, through valves, and 

 bring up the detritus of the per- 

 forated stratum, is suspended from 

 the end of a strong rope, which 

 passes over a wheel or pulley fixed 

 above the spot in which the hole is 

 made. As this rope is moved up 

 and down over the wheel, its tortion 

 gives to the bar of iron a circular 

 motion, sufficient to vary the place 

 of the cutting chisel at each descent- 

 "When the chamber is full, the 

 whole apparatus is raised quickly 

 to the surface to be unloaded, and 

 is again let down by the action of 

 the wheel. BucUand. 



According to the observations of 

 M. Arago, the greater the depth of 

 these wells, the higher is the tem- 

 perature of the waters that flow 

 from them. In an Artesian well 

 in Aberdeen, the bore is eight 

 inches in diameter, and 250 feet 

 deep, and the temperature of the 

 water three degrees above the 

 average temperature of the locality. 

 ARTI'CULAB,. (articularis, Lat. articu- 

 laire, Fr. artwolaire, It.) Belong- 

 ing to the joints. 



