C H A
C H A
after wheat, they fow peafe and vetches; in the fowilig of | thefe, they are particularly forced to wait fur fair weather, becaufe of the land"s binding. Mortimers Hufbandry. Chalk^wk-j, in medicine, is ufed for the concretions of tkl- carious matter in the hands and feet of people violently afflict- ed with the gout Lewcnhoek has been at the pains of ex- amining thefe by the microfcope. He divides them into three parts. The firft part is compofed of various final! parcels of matter, looking like grains of white fand : this is harder and drier, and alfo whiter than the reft. When examined with large magnifiers, thefe are found to be compofed of oblong particles, laid clofely and evenly together: tho' the whole fmall ftones are opake, thefe component parts of them arc pellucid, and refemble pieces of horfe hair cut fhort, only that they are fomewhat pointed at both ends. Thefe are fo extremely thin, that Mr. Lcwenhoek computes that a thoufand of them placed together would not amount to the fee of one hair of our heads. The whole ftones in this harder part of the chalk, are not compofed of thefe particles, but there are confufedly thrown among them fome broken parts of other fubftances, and in a few places fome globules of blood, and fmall remains of other juices.
The fecond kind of chalky matter is lefs hard and lefs white than the former, and is compofed of fragments or irregular parts of thofe oblong bodies which compofe the firft or hardeft kind, and thefe are mixed among tough and clear matter, in- terfperfed with the fmall and broken globules of blood difco- verable in the former, but in much greater quantity. And the third kind appears red to the naked eye, and when examin ed with glaffes, is found to be a mere tough and clammy white matter, in which a great number of globules of blood are in- terfperfed ; thefe give it the red appearance it has. Phil. Tranf. N° 1 68. p. 906. CHALKING, in cur old laws, feems to he fome duty laid on merchandize ; what it was particularly we do not find : but in the rolls of parliament it is faid, the merchants of theftaple require to be eafed of divers new impofitions, as chalking, ironage, wharfage, &c. Rot. Pari. 50 Edw. III. ap Blount Law Diet, in voc. CHALYBEATE waters. SeeMlSERAi, waters. Chalybeate wine, vinum chalybcatwn. See Wine. CHAMA, in natural hiftory, the name of a large genus of bi- valve {hells, the characters of which are thefe : it is ufually fmooih, tho' in fome places a little rugofe, and has in fome few a number of fpines. The valves of the fhell are equal, elate, and convex, and the mouth gaping, not clofmg fait, and even in all parts, as in the oifter.
The fifh contained in this genus of fhells, have all a hot tafte like that of pepper, and enflame the mouth in a troublefome manner. The French have hence called them flames and flammets, and in fome parts of the fame nation they are called lavignons and pelourdes.
The Greek word for this fpecies of fhell is (xowxgofia ; but this is followed in no other language. The anticnts ufed the fe- veral fpecies of this {hell to engrave figures on ; and as they thought proper, could give the feveral parts of the engraved figure the colours of the feveral coats of the fhell, by cutting deeper orlefs deep into it. Thus they could give the flefh of a man its natural white, and his garments a blue or a yellow, ac- cording to the nature of the fpecies of cha?na they worked on. We find feveral of thefe antique works ; and it is thought by fome, that this was the firft invention of that fort of engraved gem, which wc c,all camea.
It has been a very common error of authors to confound many of the fpecies of the chanue and oifters together ; but there are fufticient obvious diftinctions to guard againft this, notwith- standing fome flight external refemblance. 'Thechama areufual- ly fmooth on the furface, and both fhells are convex, and that more than the under fhell of the oifters, and they do not faften themfelves to one another, or tootherfubftances, as theoiftersdo. The moft remarkable fpecies in the genus of chama 1 are, i.The coucha veneris, commonly miftaken for a cockle. This has two rows of fpines, very oddly placed about its mouth, and its fides are deeply ribbed and furrowed. 2. The violet chama, of a truncated form. 3. The old woman fhell. This is wrinkled and prickly.
The chama is not only confounded with the oifter, but many Writers have alfo confounded it with the tellinse and the pecti- nes. But thefe errors are all eafily avoided, by paying a pro- per regard to the characters of each genus. The chama is of a rounder figure than the tellina, which is ufually oblong, and it is alfo thicker than the generality of tellina; and it is diltinguifhcd from the pecten by having its fhell tranfverfe and very deep, whereas thofe of the pecten are ufually flight and longitudinal. The pecten alfo is ufually auriculated, the chama never is fo.
The fpecies of the chama being very numerous, it is proper to diftinguifh them under feveral general heads. i. Of the oblong, plain, and tranfverfly Striated clmma, the ca- binets of the curious afford us the following fpecies : r . The Arabic or lettered chama, fo called becaufe its figures are fup- pofed to reprefent the Arabic characters. 2. The brown fpot- tcd Arabic chama. 3. The virgatcd chama. 4. The chama with deep tranfverfe ftria*»
2. Of thofe chama which are of an oblong figure, elate, and ftriated from the apex, we find the following fpecies. 1. The grey chama. This, when its outer coat is taken off by polifh- ing, becomes of a purple colour, and is kept in many cabi- nets as a different fpecies, under the name of the amet'hyftine chama. z. The yellow chama. 3. Thereddifh chama. 4. The variegated chama.
3. Of the rounder fhaped equilatera' chama:, we have the fol- lowing fpecies : 1. The hbatnd called the fea nut. 2. The fill chama. 5. Thegranulated chama. a. The reticulated chama, 5. The hurdle chama. The ridges in this fpecies run fo arnon°- one another, as to give it the appearance of a hurdle of flicks wound together, b. The painters chama, fo called from irs being ufed by the painters in many places to keep their colours in. 7. The cancellated chama, H. The coarfe buckram cha- ma. 9. The rugated chama. 10. T/he cbefhut chama. 11. The optic chama of Rumphius 12. The punctuated chama. 13. The variegated chama. 14. The red fafciated chama. 15. The th'm ydlow'ifh chama. 16. The fafciated amethyftine chama. 17. The thick, white, plicated, Weft-Indian chama. 1 8. The milk-white chama, called galades by Rondelctius. 19. The chama pelorides of Bellonius, fo called becaufe frequent about Peloro. 20. The chama glycymeris of /Elian, fo called be- caufe it is of a clean black colour. 21. The chama trachea, which is very rough on the furface. 22. The pepper chama, fo called from its violent tafte of pepper. 23. The chama Ima, or light chama. This is remarkable for the thinnefs of the fhell. 24. The tyger's tongue chama, a rough fpecies, fo called by Rumphius. 25. The thin, white, reticulated chama.
4. Of thofe chama: which have unequal lides, and are called chama: venerea?, we have the following fpecies : 1 . The ame- thyfline mutilated chama, with an oval hollow. 2. The oc- cidental concha veneris, with rows of fpines. 3. The oriental concha veneris. This has no fpines, but a number of wrinkles. 4. 1 he fmooth amethyfline concha veneris, with an oval aper- ture. 5, The fmooth white concha veneris, with a purplilh oval aperture. 6. The white fmooth concha veneris, with a
. grey oval aperture. 7. The fmooth white concha veneris, with a brown oval aperture. 8. The mutilated chama, with a ftri- ated apex. 9. '1 he brown, tranfverfely, ftriated, mutilated chama. 10. The variegated* agate-coloured' chama. 11. The wrinkled chama, called the old woman fhel], with prickles.
12. The larger amcthyftine chama, of the ifland of Rondo.
13. The great grey chama of Canada, of a filvcry white, with a blufh of red within. 14. The great grey chama Gf ieneo-al : this is white within. 15. The irregular ftriated chama: and, 16. The white chama with a few fpots. Hifl. Nat Eclaire, p. 322.
CHAM /EBAL ANUS, in botany, a name given by many of the Greek authors to the apios, from its having numerous tubcra among its roots, buried under the ground. Some have ex- plained the fame word as a name of the bulbocaftanum or earth nut, but it is wrong to confound two roots of fuch very different characters together, and it docs not appear that the Greek authors of note ever ufed it in any other fenfe but as the name of the apios. The name pfeudo-apios has indeed been given by fome to the bulbocaftanum roots, but it was a name founded on ignorance, and likely to produce great errors. See Tab. of Shells, N u 18.
CHAM/EBATOS, in the materia medica, the name given by fome to the common dewberry-bufh, or rubus. Dale Pharm. p. 423. See Ruuus.
CHAM.&CERASUS, the dwarf honeyfuckk, In botany, the name of a genus of plants", the characters of which are thefe : the flower confifts of one leaf, and is of a tubular form, and divided into two lips, the upper one divided into manv fer- ments, the under one whole, and of the fhape of a tongue. Thefe flowers ftand each on its feveral cup, and are placed two on the fame pedicle. The cup finally becomes a fruit, com- pofed of two berries placed clofe together, and containing each a fingle roundtfh, but flatted feed.
The fpecies of chama cer a jus enumerated by Mr. Tournefort, are thefe : 1. The alpine chamaiccrafus, with a double red fruit marked with two fpots. 2. The alpine chamacerafus, with a double black fruit. 3. The mountain chama: cer a jits, with a fingle blue fruit. 4. The bufh chamacerajus, with a double bright red fruit. Taurfi. In ft. p. 609.
Cham^cerasus is alfo ufed byDiofcorides, and fome of the old botanifts, for the alkekengi, or as we call it, the winter cherry. It had this name from its fruit greatly refembling a cherry, and the plant not growing up to a tree, but rifing only a little way from the ground. Care muft be taken in the reading the bo- tanical writers, to diftinguifh when this plant is meant by the name chama- cer a jus, and when the fhrub.
CHAM^CLEMA, in botany, a name by which fome authors call the ground-Ivy. Boerh.lnd. 172.
CHAM^EDAPHNE, in botany, a name by which Pliny and fome other authors call the vinca pervinca, or periwinkle, and others the" fpurge laurel. Ger. Erhac. Ind, 2. It is alfo ufed by Columna, and fome other authors, for the broad-leav'd ruj'cus, commonly called the Alexandrian bay, laurus Alexandrina- SeeRuscus.
Chamjedaph\E is alfo the name given by Euxbaum to a new genus of plants, not obferved by former botnniih, and found
frequently
