m A 11 E 
bearded on the upper fide. Found at Buenos Ayres in 
South America, by Commerfon. 
Propagation and Culture. The three firft are hardy, and 
-will endure the rigour of our climate. The three next 
anuft be kept in the confervatory or cape-fiove ; the lad: 
mull be preferred in the bark-dove; but none of thefe 
plants have been yet introduced in England, except the 
.fnfl: and fixth, Confidering their places of growth, in 
bogs or watery places, it will be no eafy matter to preferve 
them long with us. 
ARE'TIA, f. [from Benediclus Aretius, a clergyman 
of Berne, in the fifteenth century.] In botany, a genus of 
the pentandria r.ionogynia clafs, ranking in the natural or¬ 
der of precia;. Tlie generic characters are—Calyx : pe- 
riauthium one-leafed,'bell-fhaped, femiquinquifid, blunt- 
ilh, permanent. Corolla: monopetalous, falver-dtaped ; 
tube ovate, the length of the calyx, contracted at the neck ; 
limb five-parted ; divifions obovate. Stamina: filaments 
five, conic, in the middle of the tube, very fliort; ant here 
ereCt, dtarpifit, within the throat of the corolla. Piftillum: 
germ roundijh ; ftyle filiform, the length of the tube ; Itig- 
ma flat-headed. Pericarpium: capfule one-celled, five- 
yalved. Seeds: five.— E.JJential Char abler. Corolla, fal- 
ver-fliaped, five-cleft, tube ovate; ftigma flat-headed; 
capfule one-celled, globular, with about five feeds. 
Species, i. Aretia helvetffia, or imbricated aretia : leaves 
imbricate, Cowers fubfelfile. Root perennial, producing 
innumerable ferns forming thick tufts, which cover the 
rocks where it grows ; they rife only two or three inches, 
and are entirely covered with hard, dry, fmall, very fliort, 
leaves, having a pile of forked hairs on them. One flower 
terminates each branch : a large calyx, rough with hairs 
like the leaves, covers the whole: corolla white, with five 
bifid yellow glands and a greenilh-yellow circle at the en¬ 
trance of the tube. Fruit roundifh with angles, inclofed 
in the calyx, opening at top by five valves, whence iffhe 
two cr three blackifh oblong feeds, convex on the outfide, 
angular on.the inner fide, plunged in a fpungy receptacle 
which partly fills the capfule. The germ contains rudi¬ 
ments of five feeds, two or three of which are abortive. 
Native of the wefiern Alps of Switzerland, and of Dauphine. 
2. Aretia alpina, or linear-leaved aretia : leaves linear, 
Spreading ; flowers pedunculated. This forms a lefs hard 
turf than the foregoing with its tufts of leaves, which are 
linear, wider than the other, and drop from the bafe of the 
ferns every year. Fruit frequently abortive, but fotne- 
times it has ten or twelve feeds in dry airy fituations. Hal¬ 
ier has three varieties of this plant, i. Harder, and the 
leaves almoft fmooth ; Items covered with the old leaves, 
.;fmithing at top with a rofe of leaves that are elliptic, cili- 
ate, marked with lines, diverging, much longer; flower 
.larger; fruit round, comprelfed, five-valved. ii. More 
.rentier, with the leaves more villofe, not fpreading fo 
muck, and ihorter. The flowers are like the others, and 
ilfue from rote-like tufts of leaves, frequently from the 
fide, but from the top alfo, on peduncles two lines in 
length : flower ^ofe-coloured. iii. With the leaves and 
.calyx cpvered w ith a clofe white pile ; the flower purple. 
Thefe are found on different parts of the Swifs Alps; the 
fecond op. Mont St. Bernard, Simplon, &ij. the third in 
the GrilonSj and the valley of St. Nicholas. M. Villars 
-has alfo given three varieties, which he fufpefts may pof- 
iibly be dillinft fpecies. a. Hoary, with the hairs of the 
ieaves branching ; the flowers white, often terminating. 
b. Hirfute, with the hairs of the leaves branching; the 
fioy/ers purplifli, axillary, c. Hirfute, with the hairs of 
the leaves Ample; the flowers white, with a purple eye. 
This lalt is fometimes found with round, dry, very clofe, 
leaves, approaching to the foregoing fpecies, but removed 
front it by the axillary ieaves, and the Ample hairs. 1 lie 
■frfl: refembles it ftiil more in its terminating flowers, but 
’thefe- flowers are larger, and the leaves wider, though ga¬ 
thered ' on the fame rock. The fecond forms very fine 
tufts of red flowers on Mont St. Bernard, 400 toifes per>- 
pen^icub,r to the eaft of the tiojpiu, which is 1360 toifes 
ARE 
above the level of the fea ; and thus carries vegetation 
there to the height of near 1700 toifes, not a great deal lefs 
than two miles. This fpecies occurs alfo in Auftria. 
3. Aretia vitaliana, or grafs-leaved aretia: leaves linear, 
recurved ; flowers fubfeffile. This is a very fmall plant, 
always lying on the ground. The root, which is peren¬ 
nial, puts up many diffant tufts, forming rofes of hardifli, 
narrow, pointed, leaves, which are a little alii-coloured ; 
fruit round, fmall; with five kidney-fliaped feeds. Ac¬ 
cording to Allioni, the fruit is deeply divided into five 
parts, and contains only three feeds, two of which only 
ripen ; they are black, large, triangular, with the outer 
fide arched. Columns ohferved long (ince, that there are 
only two feeds in a capfule. Villars remarks, that there 
are the rudiments of five feeds in the germ, but that two 
always, and very often three, are abortive : he adds, that 
the receptacle is very large and fpungy; and that the hairs 
on tliis plant are branched, as in the other aretias. Na¬ 
tive of the Pyrenees, the high Alps between the Valais 
and Italy, and in Dauphine. 
Propagation and Culture. Thefe little alpine plants are 
not prelerved in gardens without fbnte difficulty. They 
require a fltady fituation ; and, if the feeds can be procured, 
they fltould be Jown as loon as poflible. They may alfo be 
propagated from offsets or flips, and by parting the roots. . 
A'RETIN (Guido), who became famous for his im¬ 
provements in mufic, lived in the thirteenth century. He 
was a native of Arezzo, in Tufcany ; and, having been 
taught the practice of mufic in his youth, and retained as 
a chorifter in that city, he Jaecame a monk of the order of 
St. Benedict. In this retirement he devoted himfelf to 
the ftudy of mufic, particularly the fyffem of the ancients, 
and, above all, to reform their method of notation. The 
difficulties that attended the inftrudlion of youth in the 
church-offices were fo great, that, as he himfelf fays, ten 
years were generally confumed barely ifi acquiring the 
knowledge of the plain fong ; and this confideration in¬ 
duced him to labour after forne amendment, that might 
facilitate inftruftion, and enable thofe employed in the 
choral office to perform the duties of it in a correft and 
decent manner. -Being at vefpers in the chapel of his mo. 
nailery., it happened that one of the offices appointed for 
that day was the hymn to-St. John, compofed by Paul, a 
deacon of the church of Aquileia, about the year 770. 
UT queant laxis REfonare jibris 
Mira gejlorum FAmuli tuorum 
SOLve pollutis LAbiis reatum, 
Sanble Joannes 
During the performance of the hymn, he remarked the 
iteration of the words, and the frequent returns of ut, re, 
mi, FA, sol, la: he obferved likewife a diffimilarity be¬ 
tween the clofenefs of the fyllable mi and the broad open 
found of fa, which he thought could not fail to imprefs 
upon the mind a lading idea of their congruitv; and im¬ 
mediately conceived a thought of applying thefe fix fy 11a- 
bles to perfect an improvement either then actually made 
by him, or under confideration, viz. that of converting the 
ancient tetrachords into hexachords. Struck with the 
difeovery, he retired to his fiudy ; and, having perfected 
his fyftem, he began to introduce it into prafiice: he tried 
the efficacy of it on the boys who were training up for the 
choral fervice, and it exceeded the mod fanguine expec¬ 
tation. “ To the admiration of all, (fays cardinal Baro¬ 
nins,) a boy thereby learnt, in a few months, what no 
man, though of great ingenuity, could before that attain 
in feveral years.” 
The fame of Guido’s invention foon fpread abroad, and 
excited in the pope, John XX. a defire to fee and converfe 
with him. The pope Pent three melfengers to invite him 
to Rome; where he was prelented to the holy father, and 
received with great kindnefs. The pope had feveral con- 
verfations with him ; and, upon fight of an antiphonary, 
which Guido had brought with him, marked with the 
Syllables agreeable to his new invention, the pope looked 
on it as a kind of prodigy ; and, ruminating on its princi- 
i 
