348 THOMAS YOUNG. 
cists of Europe, will excuse me if I complete this indis- 
cretion by stating the circumstances. 
In the year 1816 I made a tour in England with my 
scientific friend M. Gay-Lussac. Fresnel had just then 
entered on his scientific career in the most brilliant man- 
ner, by the publication of his memoir on Diffraction. 
This work which, in our opinion, contained a capital 
experiment irreconcilable with the Newtonian theory of 
light, became naturally the first subject of our discussion 
with Dr. Young. We were astonished at the numerous 
qualifications which he put upon our praises of it, until at 
length he stated to us that the very experiment which we 
so much commended had been published, so long since as 
1807, in his treatise on Natural Philosophy. This asser- 
tion did not seem to us well founded. It caused a long 
and minute discussion. Mrs. Young was present, with- 
out appearing to take any part in the conversation ; but 
we imagined that the weak fear of being designated by 
the ridiculous sobriquet of bas-bleu rendered the ladies 
of England very reserved in the presence of foreigners ; 
and our want of discernment did not strike us till the 
moment when Mrs. Young quickly quitted her place ; we 
then began to attempt excuses to her husband, until we 
saw her reénter the room carrying under her arm a large 
quarto volume. This was the first volume of the Vatural 
Philosophy. She placed it on the table, and without say- 
ing a word opened it at page 787, and pointed with her 
finger to a diagram in which the curvilinear route of the 
diffracted bands, on which the discussion turned, was the- 
oretically established. 
I trust I shall be pardoned these little details. Too 
numerous examples may almost have habituated the pub- 
lic to consider destitution, injustice, persecution, and 
