Memoirs presented to the Cambridge philosophical society on the occasion of the jubilee of Sir George Gabriel Stokes, bart., Hon. LL. D., Hon. SC. D., Lucasian professor.

tmb; ïiJQje />/io.sopM/ca/ f anisactions, Fui. N V/7t, P/l/tes 21,:22.
Pt)L tA, l~I''TE 2:1,.A.bsoerptuios by gllas o bo rax coloured witbh. 'idlSiun 0xi\de ani by a, sltiotn il water of didYni-niA.nt.i:trate eo:utai ning-l ai qiuantlity tof didymt.iuni. eqoiu to e tt.it n1 tuhe glass.
C; çC,e " S - G 0
bora glass coloured wit.
didymium
aqueoms solution of
didymnirum nitra e
ThF'o es b are 'phot s ae dis.figu'red witi horizont-ll. lines due teo dust on the sl.it of the spectroseopei
It will bt see..i that tie bFandAs are for the in)st part shifted bI- t;le borax Fut verty neoqually se;" also
tiat th.o bands are rendered more diffuse byv the borax andi soe alnimost di.ffiused way.
PLATE 22.
Alsorpftio(ns by oquiatlent su.tiont: omim didamu.i actate in acetic acid at:.d didyinii nita'miite n.
'water.
a: ' i i
shitt diîinishnis as Ith hoFnd is Ieass taefîmgîragb Fie ut th disp~erion i eth spuectriscuîo aiso Aimninisloes
as thc light is less refrangible; so the apparent di.innution of the shit is not altogether real.
Taho scetie acid. asi icr'eses the di itseises of th boadsn a s veboisr, '7nif test in tbn cse eof ot
bald. at about X471, abnld inia be te iraced i on t hetrss