ACT 



with fmall papilliform oblong tentacula ; found adhering to 

 ftones oil tiie Ihorei of the Red Sea. 15. A. viridis, 

 green and brown, with tentacula of the length of its own 

 diameter ; found attached to fiibmarine Hones at Alexan- 

 dria in Egypt, and called by the Arabs knrnjh. 1 6. A 

 jtr'i.ipus, with a cylindric body, dilated at the bafc, and 

 fpotted tentacula ; found adhering to teilaceous fifli in the 

 Red Sea, near the city Ghomfoda.' 17. A. Candida, 

 fmooth with a wrinkled foramen, and flexuous briftly tenta- 

 cula ; ranged on the ujiper margui. iH. A..hiconns, imooth, 

 of an hemifphcric oval iigure. 19. A. volva, with a cylin- 

 d;ic body plane above, and fix appendices to the orilice ; 

 found, as well as tlie tv.'o lormer Jpecies, in the Northern 

 Ocean. 20. A., rnryophylhis, red and brown, with fmall 

 pcnciliform tentacula; found in the Britilh Sea. 21. A. 

 iris, with body and tentacula obtufe and cylindric, the ex- 

 terior red, the interior bluidi, and the centre red. 2i. A. 

 fifcelhi, with longitudinal ridges tranfverfely llr'atcd, and 

 cylindric obtufe annulated tentacula ; found, as well as the 

 former fpecics, in the Norwegian Sea. 23. A. pufilla, 

 elliptic and fmooth, with a double order of rays, the exterior 

 of which are black at the apex, about the fize of a large 

 pea ; found in the ocean about the 57th degree of lati- 

 tude. 



The ait'ima fulcata of Pennant, and ccreus of Solander and 

 Ellis, which fome fuppofe to be a variety of the A. undala, 

 is the HYDRA cc7-eus in the Linna;aii fyftem by Gmelin. 

 Pennant defcribcs it as having a body marked with trifur- 

 cntcd fulci, and fummit furrounded with long (lender 

 tentacula, from 120 to 200 in number; the colour of 

 the body is pale chefnut, and of the tentacula a 

 fea-green varied with pui-ple ; it is found on the rocks 

 of the Cornifli and Anglefea feas. The A. peduncu- 

 liita of Pennant, or A. bellis of Solander and EUis, is the 

 HYDRA bellis of the Linnrcan fyftem. According to the 

 defcription of Pennant, it has a long cylindric llalk, ex- 

 panding at top and tuberculated : the tentacula are difpofed 

 in feveral ranges, (hort, and when open form a radiated an- 

 gular circumference, like a beautiful flower, with a fmooth 

 polygonal dilc ; the colour of the llalk is a fine red, and 

 that of the tentacula varied with feveral colours. This 

 fpecies, he fays, is retractile, and inhabits Cornwall. The 

 A. verrucofa of this author, or A. gemmacea of Solander and 

 Ellis, is the hydvH). gemmacea of Gmelin's I^inman fyftem. 

 According to Pennant, it has a long cylindric ftalk, and is 

 marked with elegant fmall tubercles, difpofed in ftraight lines 

 from top to bottom ; the circumference of the mouth is 

 ftriated, furrounded with Ihort petals, like thofe of the fun 

 flower, and thofe again with white tentacula, barred with 

 brown. When drawn in, it affumes the form of a bell ; and 

 the lines of the tubercles converge to the centre of the fum- 

 mit. Its body is a pale red : it inhabits Cornwall. The 

 A. pentapetala, or cinquefoil of Pennant, is the A. diatithin 

 of Ellis, with a circular contraftcd mouth ; the difc divided 

 into five lobes, covered with feveral feries of ftiort fubu'ated 

 tentacula, the ftalk fhort and thick ; when contracted it 

 affumes the torm of a long white fig ; it inhabits the rocks 

 near Haftings, Suflex. The A. hcmifpherica, or button of 

 Pennant, is the A. mefy mbryani hemum of Solander and Ellis, 

 and the hydra mefymbryctrtthemum of the Linnxan lyftem. 

 It has a fmooth (hort thick ftalk ; the edge of the difc 

 furrounded with a fingle row of tubercles, the tentacula 

 numerous and flender ; the colour a dull crimfon ; the body 

 retraftile, and flinging it-felf into the form of a conoid but- 

 ton. It inhabits moft of our rocky fliores. Pennant's 

 Zoology, vol. iv. p. 49, &c. The aftinia have only one 

 aperture both for the mouth and anus ; they feed on fhell 



ACT 



and other fmall fidt and marine animalcules, and arc tliem- 

 ftlves eatable : as they fometimes retiaft and fometimcs ex- 

 tend their tentacula, in different degrees, tlicir fonn is very- 

 variable ; the parts that are cut off are renewed ; th'-y arc 

 acutely fenfible of light, and moft of them are viviparous. 

 For a farther account of thefe animals, fee anemone, ani- 

 mal Elowf.r, and Urtica marina. See alfo Holo- 

 TiiuRiA and Hydra. 



ACTINOLITE, in Alincralogy. See Straiilstuin. 



ACTION, in a general fenf:, denotes the operation or 

 exertion of an Arm i; poiver, and \i fynonvmous with act. 

 Gramn'.arians, however, introduce fome fubtle diiUnftions 

 between thefe two ter.'.is ; reflricllng the former to ordinary 

 tranfaciion^, and the latter to thofe which are more fignal, 

 The former, fay others, relates chiefly to the perfon that 

 afts, and the latter to the cifciSla produced ; and is therefore 

 confidered as the attribute of the other : e. g. " PrefoiTC 

 prefence of mind in nil your ac'ions ; and take care that 

 they be all n:"s of equity." Some fchoolmen attempt to 

 exprcfs tlie nature of a.'^ion by a manifeftation of the power 

 or energy of a fubftar.ce, made either within or witiiout it. 

 — Accordingly it is controverted among tiieni, whctlier or 

 not a£Hoii, thus taken, be a thing diftinft both from the 

 agent, and the term or efTeft. The mod'rJIs ftand for the 

 affirmative, and the nominalijli aft'ert the negative. Thefe 

 latter obfcrve, that the aftion may be confidered two wayst 

 entitati'oely and connolalively. In the former fenfc it is what 

 we call a causk, or what mav act : and in the latter, it is 

 the fame caufe, only confidered as acting, or connoting the 

 eftect it produces. 



Actions are divided with refpeft to their principle, into 

 UNI vocal, where the effect is of the fame kind with the 

 caufe ; as the production of man by man ; and fquivocal, 

 where it is different, as the fuppofed produCtion of frogs by 

 the fun : — and again into vital ; as nutrition, rcfpiration, 

 the aCtion of the heart, &c. and not-vital, as heating. 



With refpeCt to their fubjeCt, aCtions are divided into in- 

 MANENT ; which are received within the agent that pro«- 

 duced them ; as are vital aCtions, cogitation, &:c. and tran- 

 sient, which pafs into another, as a father loves his foil, 

 and feeds and clothes him, &c. ACtions are alfo naliiral, as 

 fire hardens clay ; fiipernatural, as railing the dead ; volun- 

 tary, as the potter's moulding his clay ; and accidental, as a 

 perfon's heedlefsly dropping a glafs and breaking it ; ncccf- 

 fary, as the fun warms the earth ; and free, whai a perfon 

 chufes what food he likes, and eats it when he pleafes. 

 See liberty and necessity. 



In refpeCt of duration, aCtions are again divided into in- 

 stantaneous, where the whole cffett is produced in the 

 fame moment, as the creation of light; and successive, 

 whore the effeCt is produced by degrees ; as coiTuption, fer- 

 mentation, putrefaClion, diflolution, &c. 



Action, in Phyfwlogy, is apphed to the aCtions or func- 

 tions of the body, which are divided into the vital, na/nral, 

 and animal. The vitcd are fnch as are eflential to the fub- 

 fiftence of the individual ; fuch are the motions of the heart 

 and lungs, the fecretion of fpirits in the cerebellum, on 

 which the motions of the heart and lungs depend ; and the 

 circulation of the blood and fluids in tiieir proper veflels. 

 Pulfalion and rcfpiration are the external figns of life. 



The natural aCtions are fuch as arc neceffarj' to the con- 

 tinuance of the animal, but not fo immediately, but that it 

 may fubull fome time under a fufpenfion ot them ; as the 

 digellion of the aliment, and its convtrfion into blood. 



Under animal aCtions are comprehended thofe which 



conftitute the fenfes of touch, tafte, fmell, vifion, hearing, 



perception, imaginRtion, memory, judgment, ratiocination, 



A a 2 affections 



