60 
Proceedings of the Royal Irish Academy. 
or sodium as surely as if he held the assay in his hand — all this the 
history of the spectroscope has told us. But the spectroscope does not 
furnish us with the only point of contact between the domains of Optics 
and Chemistry, and indeed this part of the field is at present so thronged 
with labourers, that it may well be our wisdom to look for ground less 
occupied. Such ground, common to the two sciences, giving large pro- 
mise of fertility, and at present most inadequately worked, I believe 
that we have in the phenomena of polarized light. It would be im- 
possible, within the necessary limits of an address, to give you all the 
reasons for this belief. Let it sufiice to remind you, as an instance of 
the power of such an alliance, that not long since there was read before 
us here, by our eminent fellow-academician. Dr. Apjohn, the result of 
an analysis, 'which was beyond the powers of Chemistry alone, and be- 
yond the powers of Optics alone, but which was effected, successfully 
and easily, "by a combination of the two sciences. 
I would earnestly press upon chemists and physicists the impor- 
tance of this refined and powerful instrument of analysis. I cannot 
promise you that its use will be unattended by difficulty — what great 
purpose is ? On the contrary, my own experience bids me warn you 
that these difficulties are many and great. But I do say that in the 
phenomena of polarized light. Organic Chemistry possesses an instru- 
ment which she will do well to utilize — an instrument laying open to 
her a field of discovery whose limits it is not easy to see. 
And, addressing myself more especially to the physicists and che- 
mists of the Academy, I would say : Eor slackness in these depart- 
ments — and till the last year we have been slack — the state of the 
scientific world affords us no apology, l^ever were the sciences of ex- 
periment more active than they are at present. In Chemistry alone, 
and before the Hoyal Society alone, the number of communications 
has for the last ten years averaged more than twenty in the year. I 
am sure that I express the feelings of every member of this Academy 
when I say, we must not allow the present state of things to continue. 
We must not allow the reproach to attach itself to Irish science, that 
while the rest of the scientific world is advancing with rapid strides, 
we, the principal scientific society of Ireland, are alone holding back. 
I have dwelt at great, perhaps disproportioned, length, upon the 
state of the Academy with regard to the sciences of demonstration and 
the sciences of experiment, principally because our history seems to 
show that it is here we should bestow our most heedful attention, lest 
we fail in the duty which we owe to science. I must now pass rapidly 
over the remaining part of my task. 
With regard to those sciences which may be called with sufficient 
accuracy the sciences of observation, as distinguished from the sciences 
of experiment — Geology, Zoology, Botany, and Physiology — it must be 
remarked that our success or failure is not, here, as significant as in 
some other instances. We are not, here, the sole mouthpiece of Irish 
science. The Royal Geological Society, the I^atural History Society, 
the Microscopical Society, with the several societies directly connected 
