Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/544

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terpveters of the old Greeks have agreed in looking upon them as fynonymous terms. The fruit of the hippopheos, mentioned by Hippocrates, is rendered the feed of the Jlabis. ST7EBIUM, in botany, a name given by the modern Greeks to the plant called hippopbaes by Diofcoiidcs ; that author alfo fometimes called it Jlabe. See the articles Stjebe and Stjbbis. ST7ECHAS, in botany, the name of a genus of plants, the characters of which are thefe. The flower confifts of one leaf, and is of the labiated kind. The upper lip is ere& and bifid, and the lower divided into three fegments, the whole fo difpofed, that the flower has, at firft light, no ap- pearance of a labiated one, but appears meerly a plain flower of five fegments. The piftil arifes from the cup, and is fixed in the manner of a nail to the hinder part of the flower : this is furrounded by four embryos, which ripen into as many feeds, contained in the cup of the flower. To thefe marks it is to be added, that the flowers of the Jlachafes are difpofed in various feries in a fort of fcaly heads, from the fummits of which there grow certain beautiful-coloured leaves, which Clufius calls their membranaceous ligulse. See Tab. i. of Botany, Clafs 4.

The fpecies of Jiacbas, enumerated by Mr. Tournefort, are thefe. 1. The common purple_/?d?c/w, vulgarly called Ara- bian flachas. 2. The naked-ftalked Jiacbas with longer li- gulae. 3. The broad-leaved Jiachas with white flowers. 4. The Portugal Jiachas with large ligulae, variegated with rofe colour and purple. 5. The Portugal ji achat with green hairy leaves. Tourn. Inft. p. 201.

The flowers of the Jiachas are much ufed in medicine, in difeafes of the head and nerves, efpecially in fuch as are fuppofed to arife from cold caufes. They alfo promote the evacuation by urine, and by the menfes, and in fome places are efteemed one of the greateft antidotes, and given in large dofes againft the effect of poifons, and the bites of venomous animals. Mefue, and the Arabians in general, fpeak of it as a purge, and particularly as good in cafes where phlegm was to be evacuated ; though they fay it did this but flowly and weakly. At prefent we do not acknowledge any purg- ing quality in it. There is a very fragrant oil drawn from the flowers and tops of this plant, in the fame manner as that from lavender ; but it is not much in ufe with us. The flowers are an ingredient in the Venice treacle, mithri- date, ami fome other of the officinal compofitions. It is to be obferved that there is another plant, called Jla- chas, in the mops ; and by the writers on the materia me- dica, this has the epithet citrina, for its distinction from the Jiachas we have been treating of, which is either called Jl&- chas without any addition, or ftachas Arabica. The citrine Jiachas has none of the virtues of this kind, nor is it of the fame genus of plants, but of the elichryfum kind. See the article Elichrysum.

The feveral fpecies of Jiacbas are propagated by fowing the feeds in March, in a bed of dry light earth; when the young plants are about three inches high, they muft be re- moved into other beds, and placed at about fix inches dif- tance, watering and fhading them till they have taken root. They muft after this be kept clear from weeds, and fhel- tered from the feverity ef the winter by mats, or a lioht covering of peas, haulm, or other fuch matter; and in March, or the beginning of April, they may be removed in- to the places where they are to remain. The poorer the foil is, in which they are planted, the better they will flrand the winter, and the more fragant will be their flowers. They may be propagated by cuttings planted in fpring, but the feeds ripening very well with us, the railing them from thofe is the much better way. Miller's Gaoi» Diet. STAFF (Cycl.)— This is ufed as an inftrument for taking ac- ceflible, or inaccefiible heights. The manner of operation, in taking the height of an acceffible object, is as follows. Let there be placed perpendicularly in the ground a longer Jiaff DE, likewife a fhorter one FG, fo as the obfervator

may fee A, the top ]A of the height to be mcafured, over the ends D, F of the two Jiaves ; let F H and D C, parallel to the horizon, meet DE and AB in H and C, then the tri- angle FHD, DC A, {hall be Equiangu- lar; for the angles at C and H are right ones, likewife the angle A is equal to the angle FDH (by 29. 1. Euclid) wherefore the remaining angles DFH, and ADC, are alfo equal; and FH ; HD : : D C : CA, /. e. as the diftance of the ftaves, to the excefs of the longer Jiaff above the fhorter ; fo is the diftance of the longer Jiaff from the object, to the excefs of the height of the object above

By'

G E

b

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the longer ftaff Hence C A may be found by the Rule of Three ; to which if D E, the length of the longer Jiaff, be added, you will have the whole height of the object. Tr. Pract. Geom. p. 19, feq.

Inaccefiible heights may likewife be taken by means of two Jiaves. This muft be done at two ftations in a rich* line from the object, at each of which the/Wj are to be placed in fuch a manner, that the fummit, or top of the height* may be feen along their tops in the fame right line. Thus* fuppofe A the fummit of the object whofe height is to be a meafured,DE, FG, the two Jiaves at the firft ftation; and RN,KO, the feme Jiaves at the fecond, fo placed, that the points FDA, KN A, are in the fame: right line. Through the point N let there be drawn the right line N P, parallel to F A : wherefore in the triangles KNP, K A F, the angles

N,-

o

IV

H

1

£ B

KNP, KAF, are equal; alfo the angle AKF is common to both; confequently the remaining angles KPN, KFA, are equal. And PN : FA : : KP : KF. But the triangles PNL, FAS, arefimilar; therefore PN : FA : : NL : SA. Thence alternately KP : NL : : KF : SA; i. e. as the ex- cefs of the diftance of the Jiaves at the fecond ftation above their diftance at the firft, to the difference of their lengths; fo the diftance of the two ftations of the fhorter ftaff to the excefs of the height fought above the height of the ftiorter Jiaff- Wherefore S A may be found by the Rule of Three; to which add the height of the (horttr Jiaff, and the fum will give the whole inacceifible height A B. Tr. Pract. Geom. p. 22. See the articles Height and Altitude, Cycl.

Staves may be ufed for meafuring any diftance, fuppofe A B, to one of whofe extremities v/e have accefs. Let there be a Jiaff fixed at the point A, then going back to fome fenfible diftance, in the fame right line ; let another be fixed

in C, fo that both £■•'£- the points A and

I ,','.'-.'!■/. H B may be covered


 * C£ : '"'•-..., or hid by the Jiaff

\ "'*""'.., C. Likewife go-

i '""*■'■.. * n S off in a perpen-


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'•£ j£ — ^- right line C B at

r A B the point A, ht

there be placed another Jiaff at H ; and in the right line C G K, perpendicular to the fame C B at the point C, and at fuch a point of it K, that the points K, H and B, may be in the fame right line, let there be fixed a fourth Jiaff. Let there be drawn, or fuppofed to be drawn a right line H G parallel to C A. The triangles KHG, HAB, will be equiangular : wherefore KG:GH (r= C A) : : A H : A B ; 1. e. as the excefs of C K above A H is to the diftance be- twixt the firft and fecond Jiaff; fo is the diftance betwixt the firft and third Jiaff to the diftance fought. Tr. Pract. Geom. p. 25. Staff, or Catheter, in furgery. The procefs of cutting for the ftone, called the high operation, having been attended with fome inconveniencies, which occafioned its being haftily left off, Mr. Cleland has attempted to remedy thofe inconveniencies, by means of a catheter of a peculiar ftructure, which he is of opinion, had it been known at that time when this ope- ration was fet on foot and mifcarried, would have turned the advantage of the methods to the fide of the high opera- tion, and made it allowed much preferable to anv other me- thod hitherto pradtifed, and hopes that it will be yet brought into ufe, and revive that method.

The catheter is to be made either of filver or fteel, and may be of different fizes to fuit different ages. It has the outward appearance of the common catheter, and will an- fwer all the fame ufes ; but in refpect of this operation it differs from the common one, in that it is compofed of two legs with blunt points, a long tube, a Aiding bolt, and a handle, which ferves to open and fhut the legs. The bolt, which is fixed to the extremity of the tube, goes into two holes fixed in the plate of the handle ; the one ferves to keep the legs clofe during the time it is to be introduced into the bladder, and the other to extend them to the diftance of an inch or more, during the time that the operation is per- forming. The ftructure of this catheter is well expreffed by fome figures given in N°40i of the Philofophica! Tranfaclions, and the manner of ufing it is this: after having taken the ne- ceffary precautions, and filled the bladder, the catheter is to be introduced into the bladder with its points fhut ; then unbolt it at the handle, and by holding the tube in one hand, and the handle that moves the legs in the other, turn or open the legs till the bolt becomes o^pofite to the fecond 1 hole