It will not be convenient to refer to a "preliminary notice" which appeared so long since in lieu of an abstract of the present paper. We shall be glad if you will kindly furnish a brief abstract noting those points which have been added to the paper since the preliminary notice appeared. As the paper is to read on the 28th inst. [instant], it is important that we should have the abstract in our hands at once. It should reach us certainly not later than Saturday.
I am, yours truly,
Asst. Sec. R.S. [Assistant Secretary, Royal Society]'.