= 
W. P. Riddell on Soleil’s Saccharimeter. 175 
The Feejees may be an example of a rise at the west side of a 
group, and possibly a subsidence on the east; while a little far- 
ther east, the Tonga Islands constitute another extended area of 
' elevation. We observe that while the Samoan Islands afford no 
evidences of elevation, the Tonga Islands on the south have been 
raised, and also the Fakaafo Group and others on ‘the north. 
_ € cannot, therefore, distinguish any evidence that a general 
nse is or has been in progress; yet some large areas appear to 
have been simultaneously affected, although the action has often 
been isolated. Metia and Elizabeth Island may have risen ab- 
tuptly : but.the changes of level in the Feejees and the Friendly 
Islands, appear to have taken place by a gradual action. 
—— 
Arr. XX.—On Soleil's Saccharimeter; by W. P. Rippett, 
A.B., New Orleans, Louisiana. 
Tars instrument, so beautiful in theory, and so exact in its 
Practical operations for the analysis of sugars, syrups an mo- 
sses, depends upon that peculiar property of light termed circu- 
polarization ; a modification first noticed by M. Arago in 
“rystal quartz, or rock crystal. 
oarization.—The Newtonian theory of the materiality of 
ula, Of Polarized light, whose planes of vibration ate perpendic- 
ular toeach other. If again we bring these two of vibra- 
Moduced by vibrations in one plane oly, we ee two 
- It might seem ter at all into the subject of polarization, as 
ABR unnecessary to enter at all into _ ud} : ho 
rothing new is ‘ Ww! lication plain, to those w 
. offered ; yet to render the following app rg P. For ' 
icy or cn the matter ho previous study, it was tho 
"SW Of the received notions respecting it 
