1895. ] NEW YORK ACADEMY OF SCIENCES. 183 
to work (2); the lack of quiescence of the liquid surface; (3) 
the impossibility of excluding other light from the surface, and 
(4) the rapidity of oxidization of the molten gold. The results 
were therefore altogether untrustworthy as quantitative meas- 
urements. Hence no attempt was made to compare them with 
results given by Cauchy’s formulae. 
Molten iron was also made the subject of similar observations 
with equally unsatisfactory results. 
XVI. 
Discussion oF RESULTS. 
All of the comparisons made between eXperimental determi- 
nations and calculated values are condensed in the following 
tables. 
oe = — 
URANIUM GLASS. PLATINUM. SILVER. 
eet ape bh oe |2la|4 | ele (8 
| = = Fae beds A Sa ees | xi Sees 
4/4) a| & | 4]/4&)/_a/8 4 ]/e&)a|8 
| 3 | eee | —E 
| 8734] .858 | .351 7| | 80 | .929 | .834 |—.005| | go | .789 | .762 |+.027 
.298 | ..315 |—.022 | 70 | .610 | .655 |—.045 | 7 | .73L | .716 |4.015 
| 80 | .245 | .251 |—.006 | | 60 | 481 | .492 |—.011 | 70 | .644| .655 |—.011 
| 7 | .191 | .206 |—.015 50 | .349 | .341 |+.008 | 65 | .592 | .588 |+.004 
70 | .139 | .153 |—.014 40 | .191 | .216 |—.025 60 | .517 | .519 |—.002! 
65 | .098 | .125 |—.027 | 3 099 | .117 |—.018 55 | .429 | .446 |—.017 
50 | .039 | .058 |—.019 eo it es | 50 | .354 | .376 |—.022 
| aC 45 | .297 | .309 |—.012 
| 40 | .254 | .246 |+.008 
35 189 -190 |—.001 
| 30 | 139 | .140 |—001 
In view of the general agreement between the observed and 
calculated values, and in view of the further fact of the colora- 
tion of the images at large angles, so beautifully accounted for 
by the reflection theory, it may be considered that the phenom- 
enon of polarization of light by emission has thus been quanti- 
tatively proyen to be a phenomenon of reflection and refraction. 
-It will be remembered that the apparently insuperable objec- 
tion to the explanation which Arago offered was that that expla- 
nation attributed to all of the surface molecules the property of 
emitting natural light, and gave as the entire cause of the polar- 
ization, the refraction of light which works its way up from a 
certain depth beneath the surface. 
The above calculations were all made upon the assumption 
