TasBLE VI.—Indices of Refraction calculated from the exponential law. 
n 
Formula p = x 
~ * 
hn 
En 
Media of each observer arranged in the order of agreement with the observed indices. 
I. Fraunhofer’s Observations. 
Media ......... n.| *B. HC, ME, bad #G, *H. 
Crown-glass No. 9 .../1°9|1°525844|175268 52|1°529542|1°533024|1°536085|1°541629 1°546569 
Water, 1 & 2, T.18°°75. 1°6/1°330989) 1°3 32697|1°3 33 540) 1°33 5843]1°337807|1°341252|1'344221 
Crown-glass M ...... 12*0| 1°554.770/1°555933|1°559063|1°563 160|1°566794)1°573463 1°579467 
Sol. potash, T. 21°*5..|1°7|1.399639|1'400504|1°402777|1°405653|1°408 13 1|1°412526|1°416357 
Crown-glass No. 13...)1°9|1°524.314)1°525306|1°527953|1°531382|1°534391|1°539846|1°544704 
Oil of turpentine...... 2°1|1°470480|1°471553/1°4.74456|1°478303/1°481750)1°488134)1°493940 
Flint-glass No. 13. .../2°1|1°627729/|1°629686|1°6 3 5000) 1°642060)1'648408/1°660210|1°67 1017 
Flint-glass No. 30. .../2°2/1°623550|1°6254.51|1°630547/1°637391|1°64.3604|1°655276|1°666079 
Flint-glass 23 (1&2)../2°2|1°626571/1°628424|1°633533|1°640573|1'646877|1'658723|1'669683 
Flint-glass No. 3...... 2'2|1°602092)1°603775|1°608379 |1°6 145 59|1°620156|1°630686)1°640410 
II. Rudberg’s Observations. 
Topaz, 2nd axis ...... 1°7|1°608405| 1°609285) 1°611591| 1°614518) 1°617030| 1°621493|1°625370 
Quartz ex. ray......++. 1°7|1°54.9902|1°5 50822/1°5 53239 1°5 56300) 1°558933 1°563608)1°567675] | 
Arragonite, 1st axis...|1°g9|1°527485|1°528207|1°530127/1°532614 1°534790/1°538731|1°542241 
Quartz O. ray ......... 1°7|1°540908)1°54.1804)1°544.146/1°547111 1°549672/1°554199|1'5 58 148 
Topaz, 3rd axis ...... 7 1°6105213/1°611401/1°613706|1°616623 1°619130|1°623580)/1°627457 
Cale-spar O. ray ...... 1°9|1°6 53084] 1°654.553|1°658471|1°663 547 1°668019/1°676133/1°683 372 
Topaz, ISt AXIS ...+0. |1°8/1°617927|1°618796|1°621088|1'624025) 1°626574|1°631148\1°635168 
Arragonite, 3rd axis..|/1°9/1°676367|1°677763|1°681494|1°6863 32) 1°690584|1°698302|1°705 182 
Cale-spar ex. ray...... 2°1|1°483833/1°484483/1'486237|/1°4885 58/ 1°490630/1°4944.64|1'497945 
Arragonite, 2nd axis... 2°0| 1°68067 5] 1°68206 5|1°68 58 10|1°690713|1°695067|1°703061)1°7 102 
III. Powell’s Observations. 
Sulphate of magnesia.|1°4 
Oil of anise, T.20°'g..]2°8 
Oil of anise, T.13°°25..)2°8 
Sol. of potash, T.16°..]1°4. 
Sulphate of soda . ...}1°6 
Nitrate of lead ...... 1°8 
Superacetate of lead..|1°9 
Nitrate of bismuth ...|1°7 
Nitric ACid | <........00s 2°1 
Subacetate of lead ...|1°8 
Oil of sassafras ... ..|2°7 
ATeON OMS nat ssscnncrs '7 
Muriate of lime I'g 
Muriate of ammonia..|1°8 
Oil of anise, T. 15°°1..|2°8 
Muriatic acid ......... 1°4]1°4.04948] 1°406173|1'409243] 1°4.13004|1°4.16155|1°421578|1°426167 
Sulphuric acid......... 10} 1°4.32051|1°4.32967/1°43 5250] 1°43.7921| 144007 1/1°443612|1°446482 
Rock-salt'.........sss00+ 2°2|1°54.0232|1°54.1516/1°54.5027/1°54973011°553990|1'561969|1'569323 
Nitrate of mercury ...|1°8]1°34.0966| 1°34.1733]1°34.3764]1°34.63 59|1°34.8614|1'°352660/1°3 56220) 
2°5)1°5§31891}1°533613) 1°53 3443/1545 145) 1°551414)1°563 568) 1°57519 
+++{2°O] 1°373285] 1°374.007| 1°37 5950|1°378490|1°380744|1°384.860| 1°388566 
Bisulphide of carbon..|2° 5] 1°618 343] 1°621648/1°630847/1°64.3690|1'655795|1°679461/1°702390) 
; 2°0| 1°33 1840}1°3 32.489) 1°3 34233) 1°336515/1°338534/1°342229/1°345 546 
Oil of cassia, T. 14°...]3°5]1°594.749]1°597716|1°606756|1°620875|1°635542|1°66764.5|1°702529) 
176] 1°4.0348 5] 1°4.04.500/1°407139|1°4.10441|1°4.13263)1°419217/1°422492 
++4/2°6)1°34012 5) 1°340651/1°342136]1°344210)1°346159)1°34.9946|1°3 53572 
2°4}1°346201] 1°346845) 1°348638)1°3 5 1086|1°3.53342/1°357648|1°361690 
Oil of cassia, T.22°°5..]3°4]1°590247]1°593 184] 1°60244.3| 1°61674 3) 1°63 14.66] 1°663353)|1°697635 
Oil of cassia, T. 10° ..]3°2]1°5968 19] 1°600068) 1°609743]1°624.364] 1°639132)1°6 70436] 1°703372 
NOKCOSOLE Sos ausenepsees 
Pyroligneous acid 
Water, T. 15°°3 *..:.. 
Solution of soda 
Muriate of baryta 
Nitrate of potash 
Oil of Anise further corrected for Temperature. 
1°343422/1°344 187 
1°545105/1°547251 
1°54827 3] 1°550374 
1°402507|1'403496 
1°339170|1°339902 
1°345458)1°346195 
1°342956/1°343646 
1°330709/1°331393 
1°398821/1°399823 
1°33.5024|1°335687 
17525786] 17527416 
1°362743/1°363443 
1°400651/1°401556 
1°349979|1°3 50740 
1°548690]1°550828 
1°348551 
1°562296 
1°565013 
1409125 
1°344198 
1°350631 
1°347874 
1335458 
1°346148 
1°553423 
1°556375 
1°406027 
1°34 1811 
1°348 142 
1345491 
1°333189 
1°350559|1°3 54008) 1°3 56922 
1°570857|1°588079|1°605172 
1°573344|1°590098|1°6067 10 
1°4.11722|1°416183/1°419953 
1°34.62.32]1°349805|1°3 52882 
1°352798|1°3 56678) 1°360093 
1°349964/1°353753/1°357118 
1°337412|1°340879|1°343892 
1°406129 
1°339683 
1°538667 
1367599 
1°402537 
1°337440 
1°532054 
1°365277 
1409351) 1°415348/1°420740 
1°34.1632|1°345121/1°348190 
1°544915|1°557347|1°569485 
1°369596|1°373138/1°3 76218 
1°403968 
1352739 
1°556970 
1°407090 
"355323 
1°565803 
1°40983 5/1°4.14803/1°419233 
1°357559|1°361568) 1°36 5098 
1°574323)1°591457|1'608423 
- | Oil of anise, T. 13°'25.]2°8]1°54.8290) 1°5 50380) 1°5 56382) 1°56 5013] 1°5734.10|1°590080 1°606673 
Oil of anise, T. 15°°x.)2°8]1°54867311°550814| 1°5 56958|1°565798|1°574320|1°5914.76|1°608500 
Oil of anise, T. 20°°9.|2°8)1°54.5120)1°54.7265|1°5 $34.30|1°562296|1°570850|1°588052/1°605 122 
