175 
! 
It will be seen that my results are not reconcilable with 
the last formula, whereas in some cases, especially in that 
of sublimed alizarine, the composition found agrees tolerably 
well with the new formula C 14 H 8 0 4 . The great excess of 
hydrogen found even in the case of well crystallised and 
apparently quite pure alizarine remains to be explained, 
and though unwilling to throw any doubt on the complete 
identity of the natural and artificial product, I confess I 
look forward with great interest to the full confirmation of 
this remarkable discovery. 
The following extract of a letter from Mr. Wm. Rayner 
Wood, to the Chairman, dated April 3, 1869, was read : — 
“ Having read the notices of the earthquake of the 15th 
March in the Society’s proceedings, I think that a state- 
ment of my own experience may be interesting in connection 
with them. 
“In consequence of indisposition, I had gone to bed 
about half-past five, and was asleep. I was awakened 
a few minutes past six by a noise which I at first thought 
was thunder, but which seemed much beyond thunder 
or any noise I ever heard. My next thought was that 
a stack of chimneys must have fallen upon and through the 
roof and successive floors below. I mention these successive 
thoughts as indications of the violence of the sound and the 
length of time that it continued. The noise ceased with a 
great rattle of the window shutters, such as I have never 
heard in any wind, however high, though I have occupied 
the same room for five and twenty years. I felt no shock, 
probably from my being in bed. My servants who were in 
