1802.] 
merits the greateft attention. We fee 
there that above Taupuramune, a village 
fituated a hundred Jeagues from the mouth, 
eleven rivers empty themfelves into the 
Miuoni; thefe are the Arrenneen, the 
‘Toppanawin, the Errewin, the Cowom- 
ma, the Pourakecte, the Arrowa, the Ar- 
recowene, the Waoune, the Anape, the 
Aunime, and the Carapion. The vigo- 
‘rous and very remarkable paintings which 
arc met with at about ten days journcy 
_ above j aupuramune, are found to be con- 
fiimed by the relations of fome modern 
‘travellers, who have advanced to the fame 
counrry by other rivers. Therivers men- 
tioned by Harcourt, are alfo indicated’ 
un‘er the fame names, and placed in the . 
fame order, on the grand Spanifh chart of 
South America, drawn up by Don Juan 
DE La CruzCaNno_ It is true that the 
Spanifhchar: refers them,norto the Maroni, 
but to the river of Surinam, of which they 
form, in it, the upper part: but this is a 
miftake. It was of little importance, 
however, fo long as it was only found in 
a chart almoft unknown: but ic is become 
neceliary to rectify it, as the Englifh, after 
having reduced the colony of Surinam, 
have entirely copied and publifhed the 
Spanifh chart. The Court of Madrid 
judged it expedient to fupprefs it foon 
after it had been publifhed in Spain. The 
French engineers of Cayenne have already 
acknowledged, as branches of the Maron, 
the rivers of Arrova and Wahoni, which 
Jaft is the Wayoune of Harcourt. This 
is {ufficient, if not to demonftrate, at leatt 
to point out more ftrongly, an error which 
could not be always°a matter of indif- 
ference were it to be adopted longer. 
We mutt, .therefore, till we have more 
authentic documents, refer to the courfe 
ot the Maroni, the eleven rivers, of which 
the Spanifh chart has formed the upper 
part of Surinam. 
=F BL Bao 
ROYAL SOCIETY OF LONDON*. 
OPTICS. ; 
R. Everarp Home, in a paper 
read before the Royal Society, No- 
vember 5, 1801, has ftated {ome facts and 
obfervations, in fupport of an opinion, 
advanced by him in a former lecture, tinat 
the adjuftment of the eye to fee objects 
at different diftances, does not depend 
* Notice of the papers publithed in the 
‘firft part of the volume of the Tranfaétions 
‘of the Royal Society for the Year 1802. 
Erratum.—lIn the laft Number, p. 486, 
for 1822, read 1301. 
Proceedings of Learned Societies. 
567 
upon any internal changes in the cryftal- 
Jine lens. 
It appears, from the handfome tribute 
paid by Mr. Home to the memory of the 
Jate Mr. Ramfden, that the experiments 
upon which thele facts are founded, were 
conducted by the united talents of both 
thefe gentlemen. So long ago as the year 
1794, Mr. Home was fatisfied, as; the 
refult of various experiments, that the 
removal of the cryttalline lens did not de- 
prive the eye of the power of feeing dil- 
tinctly at different diftances. The great 
importance of this fubjeét led Dr. Young 
to examine It with much attention, and 
his conclufions coincided with the gene- 
rally adopted theory, that the adjuftment 
of the eye todiffvrent diltances does depend 
upon the cryftalline lens. This difference 
of opinion led Mr. Home to cal! in the 
affitance of Sir Henry ENGLEFIE£LD, 
who is much in the habit of optical expe- 
riments, and who, with Dr. Young’s op- 
tometer, made many experiments upon 
himfelf and others, from which he infer- 
red, that the theory adopted by Mr, 
Home is agreeable to fa&. 
In the Bakerian le&ture, Dr. Younc has 
given a very elaborate and learned dif- 
courle on the theory of light and colours: 
the objeét of which is not fo much to pro- 
pole new opinions, as to fupport, by ad- 
ditional evidence, theories already ad- 
vanced, 
The three effential hypothefes noticed 
by Dr. Young, and confidered by him li- 
terally as parts of the more complicated 
Newtonian fyfem, are—r. That a lumini- 
Jerous ether pervades the univerfe, rare 
and elofiic'in a high degree. 2. That un- 
dulations are excited in this ether, when-~ 
ever a_ body becomes luminous; and 4. 
That the fenfaiion of diferent colours de- 
pends on the different frequency of vibra. 
tions excited by light in the retina. Thee 
hypotheles are, in the paper before us, 
fupported ‘principally by quotations from 
various parts of Sir Ifaac Newson’s writ- 
ings. The fourth hypothelis, viz. that all 
material bodies have aa attraction for the 
ethereal medium, by means of which it is 
accumulated within their fubjiance, and for 
a fmail diftance around them, in a fate of 
greater denfity, but not of greater elafitcity, 
is diametrically oppofite to thar of New- 
ton, but confidered by Dr. Young as the 
mott fimple, and-beit capable of explaining 
the phenoinena ; and, a!tnough he does nor 
propole it as a fundaniehtal hy potheis, yet 
he has endeavoured to’ demonttrate its 
truth, by a. long. feries of well-fupporidd 
propoftions; from all which he con- 
cludes, 
