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kept in a flo'urifhing ftate for fome time by the wet earth in the box. Thefe experiments fhew us a ufe in the feve- ral parts of the Visor; of plants, which providence has wifely allotted For the fervrce of the whole, and which we can otherwife have no idea of. Every part of the roots of the fame plant is thus found to be capable of (applying all the reft ; and it is evident, that the feveral portions of the roots in the mint communicate owe with another by means of vef- jfels which ferve only to carry water from the one to the other ^ without mixing it with the juices of the plant. Such vef- lels of communication there muft have been between the two fets of rests of this mint, which muft have pafled thro' that part of the ftalk of the plant, which was be- tween the two joints, tho' feveral inches in length, and by thefe While one root was kept moift, the other was moiftened by it, whether the upper one, or the lower one was in the moift place, and then the nourifhment was carried up by both to the plant.
From this we fee the great ufe of tap roots to plants^ and underftand the realbn why the lucerne, faint-foin, and 'other plants which have long tap roots produce fuch nume- rous branches and fucceed to well in dry fealbns, when the fhorter rooted plants are nearly deftroyed. The earth at a great depth is always moift, and thefe tap roots pene- trating to that depth imbibe that moifture, and fend it up to the upper roots-, which difcharge it into the earth near the furface, as the upper roots of the mint do into the ■earth, in the trough; and thence all the fibrillseof the whole fct of horizontal roots are fupplied with a proper degree of moifture in the earth, where they run and grow almoft as well as in moift weather. If this was not the cafe, the ■roots which are fpread thro' the upper furface of the earth 'cefuld he of no fervice to the plant in dry weather. The ftirring of the earth about the roots of plants has been a •practice long ufed by our gardiners, who were well ac- quainted with the effects of it, tho' ignorant of its caufe. The roots of plants fend out horizontal fibres every way, and thefe fend out fibrillar on every fide from them, which run thro' the whole upper ftratum of vegetable mould : every time this mould is ftirred, a great number of thefe fibres and nbiillre are broken off, and the confequence of this is, that they encreafe in number, feveral new roots always fhooting out in the place of one that was broken off j and as the number of roots is the great means of the fupply of a plant, every time the earth is ftirred, that number, and confequehtly that fupply is encreafed. There feems no danger of the plant's being furfcited by an 6ver fupply of nouriihment this way j for we fee nature has provided for a difcharge of the abundant moifture by the other rests, as we find by the water difcharged into the earth in the trough. It remains yet to try whether the fluid thus evacuated be pure water as received, or be al- tered into the nature of the plant. This cannot beeafily determined by mint ; but if a ftronger flavoured plant, fuch as garlick, be fet in water* and part of its roots placed in a bed of flower inftead of earth, it will be foon feen whether the flower in this cafe be moiftened as the earth in the other, and the tafting it will fhew whether it be moiftened with pure water, or with water altered to the tafte and nature of the plant. Tuffs Horfehoeing Huf- bandry. Preparation of Roots, there are feveral ways of preparing roofs for medicinal ufe in the caftern nations, which rtrong- ly alter them from their original form and appearance. An inftance we have of this in the drug called falefo which is no other than the root of an orchis thus prepared. See the article Salep.
Other roots they alfo prepare in the fame manner, or fome- thing like it ; an inftance of which we have in fome of the oriental ginfeng, which is clear and pellucid as a refin, and friable like one, retaining very little of the ftructurc or appearance of the root, kempfer gives the method by which the people in the eaft do this, and it may be well worth trying on fome of our own roots. The Chinefe, this author informs us, give their ginfen<* its colour and tranfparence in this manner. They mace- rate the frefh root for three days in cold rice water, then expofe it in clofe veftels, to the vapour of the fame water j after which they carefully and leifurely dry it, and it becomes hard and brittle, of a brownifh red colour, and as tranfparent as a refin.
All the ginfeng of China is not of this fort, and it has been fuppofed by fome, that fuch as was fo, had aflumed that appearance by age, as many of the more fucculent roots, which have very fmall fibres, will become much lefs opake when perfectly dry, than they were at firft ; but ex- perience ihews that this is not the cafe, for many perfons have kept the oriental ginfeng a great many years, but it has never been known to aflume that appearance. There is no doubt however, but that if the Weft Indian ginfeng were treated in this manner, it would equal the prepared ginfeng of the eaft: for the roots of fome of our umbel- liferous plants, particularly the fkirret, may be made clear nnd tranfparent in this manner, by only boiling it in com-
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mon water, and afterwards drying it in the open air. Mem' Acad. Scieri. Par. 1740.
.F/smw -Roots. See the article Flowed.
Root of ofieocolla, a word ufed to exprefs a fort of foft and rotten matter, on which the ofieocolla of Germany is found in fandy grounds.
The workmen feek after the ofieocolla by the direction of certain lumps, of a white marley matter, which they find lying on the fands ; under this they always find a parcel of rotten vegetable matter, branching out from a main Item or trunk, at ten or twelve feet deep up to the furface ; this rot- ten fubftance they call the root of the ofieocolla ; and they obferve, that where the matter they feek after is not found round it at the time of their digging, they need only mark the place, and dig again a year afterwards, and they will find it formed in a perfect manner. The ofieocolla found near Frankfort is all of this kind ; and we find the holes in the center of all the pieces, through whish this root had pafled. It is fo tender that it ufually moulders away on the ofieocolla, being expofed to the air ; but fometimes they wafti it out. Phil. Tranf. N° 39. Sec Osteocolia. It is not eafy to conceive what this is, unlefs the remains of foftile branchws of trees ; but even then it is as difficult to account for the formation of the ofieocolla about them, as there is none of it found concreted where they are not. We have a fort of ofieocolla found with us in what we call pe- trifying fprings ; but as this is done in the water, it is eafier to conceive how it becomes fo pure, than how a foft and pappy fubftance found in the midft of a bed of fand, comes not to have fome fand embodied in it.
Root, in mathematics (Gy/.J— The extraction of the roots of algebraic quantities, may be performed in a manner analogous to that ufed in arithmetic, for extracting the roots of numbers ; and if the root cannot be accurately found, the procefs may be continued indefinitely, which will give a feries. Thus the quantity aa + xx being pro- pofed, its fquare root thus extracted will be found to be>
« + ■
,+ '
ia 8«' ' i6o J 1280' "*" 2560' Sec Newton's Meth. of Fluxions & inf. feries, p. Mr. Cohan's Edit.
, tfc.
4. of
But the extraction of roots may be abbreviated by that great author's binomial theorem, which he thus exprcfles in his letter to Oldenburgh.
P + PQ> i = p!+ 2-AQ.+ J^i BO -t. m - 2n
n in j»
CQ.+ m=5?DQX, faVi
4" Where P + P Q_ fignifies the quantity whofe root' or dimenfion, or root of any dimenfion, is to be in- veftigated. P, is the firft term of the quantity ; Q_, the reft of the terms divided by the firft. And
— is the index of the dimenfion or power of P •+- P Q.,
whether that denomination be a whole number, a fraffion. affirmative or negative. Laftly, A, B, C, D, &V. reprefent the terms of the root as they are found ; that is, A ftarids for
the firft term P ~, B for the fecond "AQ^, csV. The
h ufe of the rule will appear by a few examples. l.Tofind the fquare root of cc 4- x x ; that is, </cc 4- xx, or ce 4- xx '• SubftitutingrcforP,^forQ_, i for m, 2 for*,
cTli = t= P T = A, fcfr. we (hall ] lave
ce 4- xx
, * x x*
c + r7-Tr :
+
ibe
2. In like manner-
y
f-
= orNxj'- a z y '
Will
be found equal to N X — 4-
+
y 33' 9 y
+ ,4 "- +
ForPr
— yy ~
Klyl 3> A:
ar«
! x — i
- y
a n
- =-AQ = ,
Thu
"it el a . . — — — I. «<"•
y y 3>
3. Simple powers may be found in the fame way.
if d 4- e, or d 4- e were required. Then by the rule P — d,
0-= J-> m = 5, anil n ss 1. Hence, A = P V =.d i ,
eZ — ^de*, F = t ! ; and laftly, G =: m ~ 5 *F Q =0 ,
bn s
Here the feries terminates, and therefore d-\-e =s d s -f- Sd*l-\- 10 d' ;• 4- tod* e.'+ S^e" + e'.
4. Di-
