Copy letter from Robert William Frederick Harrison, to Messrs Newton & Company 'Dear Sirs, Referring to your Account for microscopic slides we find that we shall not require the slide of "twelve mica films" priced at 10/6 and it is accordingly returned. Please be good enough to send in an amended bill. The charge 15/6 for the eleven other slides certainly appears to us as somewhat high. Some of the descriptive labels too are not clean. I shall be glad if you can amend this. Yours truly, Harrison Asst. Sec. RS. [Assistant Secretary, Royal Society]'. 13 May 1896