HYP
Hyperbolic Space, in the higher geometry, the area orfpTLce contained between the curve of the hyperbola, the afymptote, and the ordinate. HYPERBOLICUM Acutum> a folid made by the revolution of the infinite area of the fpacc contained between the curve of the hyperbola and its afymptote. This produces a folid in- finitely long, and yet is demonftrated to be equal to a finite folid or body. For the true fenfe of fuch expreffions fee the article Logarithmic.
HYPERICUM, St. John's Wort, in botany, the name of a genus of plants, the characters of which are thefe : The flower is of the rofaceous kind, confining of feveral leaves difpofed in a circular form ; the cup confifts alfo of feveral leaves, and from this there arifes a piftil, which finally be- comes a trigonal, three pointed, and tricapfular feed veffel, filled with fmall feeds. To thefe marks it may alfo be added, that the leaves of the Hypericum grow two at every joint. The fpecies of Hypericum, enumerated by Mr. Tournefort, are thefe :
j. The common yellow- flowered Hypericum. 2. The com- mon Hypericum? with blood-coloured fpots. 3. The mo- neywort leaved Hypericum. 4. The fhort leaved Hypericum, called the Syrian and Alexandrian St. John's wort. 5. The curled Hypericum, with triangular pointed leaves. 6. The fmallcr upright Hypericum. 7. The fmall procumbent fmooth Hypericum. 8. The larger woolly procumbent Spanifh Hy- pericum. 9. The fmaller woolly procumbent French Hype- ricum, 10. The woolly procumbent marfh Hypericum, com- monly called the marfh afcyron, or St. Peter's wort, with hoary leaves, n. The round italked upright hairy Hyperi- cum. 12. The Hypericum of mount Olympus, with leaves hairy about the edges, 13. The beautiful, not branched, broad-leaved Hypericum. 14. The large leaved perfoliate Hypericum. 15. The fquare-ftalked Hypericum, commonly called ajcyron, and St. Peter's wort. 16. -The ftone Hype- ricum, with very fine bluiffi-green leaves. 17. The ftinking fhrubby Hypericum. 18. The perfoliated and perforated leaved Hypericum. 19. The great flowered low Alpine Hy- pericum, with fpotted flowers. 20. The broad leaved Por- tugal Hypericum, with myrtle-like leaves. 21. The toad-flax • leaved Portugal Hypericum. And, 22. The fmalleft woolly Portugal Hypericum. Tourn. Inft. p. 254. Hypericum is a good vulnerary, detergent, and nervous me- dicine : It is given with fuccefs in fpitting of blood, or void- ing it by urine ; it refolvcs coagulated blood, promotes the menfes and urine, deftroys worms, and ftands recommended in all nervous cafes.
HYPERINESIS, a word ufed by Hippocrates for any exceffive evacuation, but moft frequently in the fame fenfe as byper- catharfis, an over-purging.
ITYPEROA, a word applied by authors to the upper part, or palate of the mouth, and the bafis cerebri. It properly fig- nifics any upper place.
HY'PEROCHE, in mufic, is the difference between the en- harmonic and chromatic diefes. It is expreffed by the propor- tion of 3125 to 3072 : For, 44tt = tt : 44t* Mr. bu- rling has made ufe of this term. Mifc. Berol. v. 1. p. 279,280.
HYPNOTICUS Serpens, the Jleep-fnake, in zoology, the name of an Eaft Indian fpecies of ferpent, called by the Ceylonefe nintipolong, a word importing the fame fenfe. It is of a deep blackifh brown, variegated with fpots of white, and is a very fatal kind in its poifon, its bite always bringing on a fleep which ends in death. Ray's Syn. Anim. p. 332.
HYPNUM, in botany, the name of a genus of moffes, the characters of which are thefe : The capfules or heads arg uni- form, and covered with a calyptra and operculum ; they are ufually of an oval or oblong figure, and commonly ftand on long pedicles which arife from the ajze of the leaves, and are furrounded at the bottom with a foliaceous or lanuginous bed different from the leaves. This covering of the bottom of the ftalk, is called by authors perichastium, and is itfelf a fuf- ficient diftinction of the Hypna from all other moffes, the brya, mnia, fphagna, &c. having none of them any fuch thing. To this it is to be added, that the branches of the Hypnums are ufually fpread about upon the ground, and are perennial ; and that there is what Botanifts call a fades pro- pria, or peculiar look of the plant, which at firfr. fight dif- tinguilhes the genus to an obferver ufed to fuch things. Dillen. Hift. Mufc. p. 270.
As the family of the Hypna is very numerous, they are ufu- ally divided into feveral orders. Of the firfr. order are thofe Hypna which have erect heads, or at leaft fuch as are but a little bent ; and of this order the firft feries comprehends fuch as are pennated, or whofe pinnae are placed in two, fame- times in three rows on each ftalk, or in the fame plane. The firft divilion of this feries comprehends thofe which have flat and fmooth pinnse : Of thefe the following are all the known fpecies : 1. The fmalleft yew-leaved Hypnum ; this produces its capfules always toward the fummits of the ftalks. 2. The fmall procumbent yew-leaved Hypnum ; this produces capfu- les at the bafis of the ftalk. 3. The great branched, upright, and yew-leaved bog Hypnum ; this grows in wet places, and is much larger than the two former, and branched, they be- ing only fingle leaves of half an inch or a little more in height.
HYP
4. The Acacia leaved Itypmm, with fhort pedicles; the branches of this are fhort, fometimes fimple, fometimes branched. _ 5. The double-rowed Hypnum, with crooked nns ; this is compofed of numerous branches of about an inch long, fpread every way about upon the ground. 6. The fingle rowed Hypnum, with ftraiter fins ; the pinnuUe on this ftand Ioofely together, and the ftalks are branched. 7. The glittering feather-leaved Hypnum, with oval heads ; this grows to two or three inches long, and ufually fixes itfelf on the branches of trees. 8. The trichomanes-like glittering fea- thered Hypnum ; this alfo grows on the barks of trees, but it adheres left firmly to them than the former. 9. The tranf- parent bird's-foot leaved Hypnum ; this is found in Patagonia. 10. 1 he large fuining membranaceous water Hypnum ; this grows in watery places, and is ufually two or three inches long, and the heads grow ufually from the lower part of the ftalk, though fometimes higher. Id. ibid. p. 271.
The fecond divilion of this feries of the Hypnum!, contains thofe which have undulated and curled leaves ; of thefe the following are all the known genera : 1. The trailing Hypnum with waved fins ; this is remarkably diftinguifhed from the other Hypna, by its fpreading on the ground in the manner of the Ivcopodium. 2. The wavey feathered Hypnum with fhort (banks ; this grows from two inches to fix or feven in length, and is a very beautiful kind ; it is found on the chalk- hills about Gravefend. Id. ibid. p. 274. The fecond feries of the Hypnums is that of the fern-like kinds, called by many fern-mofl'es ; thefe have their ftalks every way furrounded with leaves, and their ramifications all placed in the fame plane, fo that they referable the ferns. Of thefe the following are all the known fpecies: 1. The large fhining fern Hypnum with tamarifk leaves ; this is a very beau- tiful mofs, it grows ereft, and is fix inches high ; it is com- mon in our woods. 2. The leffer fern Hypnum with tama- rifk leaves ; the branches of this are as long as thofe of the former, but they are more flexuous, and bent in feveral parts. 3. The fine dented trailing fern Hypnum ; it .grows fome- times on the ground, and fometimes on the trunks of old trees, and is_ diftinguifhed by the remarkable fmallnefs of its leaves. ^ 4. The fhining plume fern Hypnum ; this is a fine filky kind, found not unfrequcntly on walls and old trees.
5. The tough thready hill Hypnum ; this is of a yellowifh colour, and its branches are remarkably pointed. 6. The yellow thready Hypnum ; this is a very fmall fpecies, but ufually grows in large tufts, and is found on old trees in Vir- ginia. 7. The curled fern Hypnum ; this grows to three or four inches in length, and is common in wet places in SufTex and feme other counties. 8. The plume crefted Hypnum ; this is a very elegant plant, and varies much in its fize in different foils, being very fhort, and in thick tufts in dry piaces ; and longer, and growing more Ioofely, in wet ones. 9. The fine leaved bog Hypnum ; the leaves of this kind are of a very beautiful yellowifh green, and are in moft parts of the plant rcfle&ed at their points j this is frequent in boggy places about London, as on Hampftead-heath, tSc, 10. The foft and pale glittering fern-like Hypnum ; this is common about the flumps of trees, but very rarely produces its cap- fules. Id. ibid. p. 293.
1 he third feries comprehends the fquammofe Hypnum; ; that is, fuch as have their leaves every way furrounding the ftalks in the manner of fcales. Of thefe the firft divifmn contains fuch as have their leaves and the ends of the branches bent downwards. The following are all the known fpecies of thefe : I. The curled cyprefs-like Hypnum ; this has crooked leaves, and docs not creep, but grows in large tufts, in which the feveral branches lie over one another ; it is very common [in woods about the roots of trees. 2. The yellow, wolf's-claw Hypnum ; this feldom grows to more than three inches in length, yet has very much of the appearance of the lycopo- dium. 3. The great fcorpioide creeping bog Hypnum ; this alfo (breads itfelf in the manner of the Ivcopodium, and is found in watery places in Shropfhire and eifewhere. 4. The leffer upright fcorpioide bog Hypnum ; this is a very elegant mofs, and is very frequent in boggy places in moft parts of England. 5. The creeping many-beaded water Hypnum j the branches of this fpecies are long and trailing, and ufually de- ftitute of leaves, but from their fides and extremities there iflue young (hoots covered with thick-fet and deep green ones ; it is common on the Thames fhore, but feldom pro- duces any capfules. Id. ibid. p. 292.
The fecond divifton of this feries of the Hypnums, takes in thofe which are fquammofe and dentated ; a firft fubdivifion of thefe alfo is eftablifhed, to comprehend fuch as have their leaves Handing out, whether broad or narrow. Of this fub- divifion are the following fpecies: 1. The great triangular pale-green Hypnum ; this grows to fix or feven inches fong, and is not unfrequent in woods and under hedges. 2. The moft common dented ground Hypnum with obtufe heads ■ this is very frequent at the roots of old trees, and in dry pa- ftures, and produces a great number of heads. 3 The com- mon dented ground Hypnum with fbarp beaked heads ; this alfu is very common about the flumps of trees in woods and hedges. 4. The knee-holly leaved Hypnum ; this is fmallcr and fhorter than the former, and grows in wet places upon
ftones.
