Poppelsdorf er Castle 
Ree, Paris Auer. 3 Bonrr on the Rhein 
Jn\y 30. 1857 
My dear Doctor ! 
Best thanks for your esteened letter 1 i Now is the end of 
the collep^ia, I teach l6 hours per week, and thus was in a bind 
concerning preparations, that I can answer your letter of July 
24 , which^I did not ^et until July 28,probably throuprh your 
esteened si sters^'^ You say, that you will remain in Paris still! 
8-10 days; hopefully longer to judge from the precedent in 
Berlin-, for otherwise this letter will not find you there any more.. 
I have not yet received the microscopes from Nachet; instead,, 
the purchasers push me both, and I long to get them.. If you corae 
here, you coiad occupy yourself with several microscopeff, this- 
would be wonderful, and it would be a p-reat pleasure for me, to 
be able to assist you,. A man as industrious as you^wbo^se know - 
ledge is always so all encompassing,. could take time out for the 
significant progress in the manipulation of the microscope and the 
judgeraent of microscopic paraphernalia. Do not give up this plan ! 
In Helmholtz you have here in Physiology one of the most oustan - 
ding persons. He is the inventor of the eye-mirror and occupies 
himself primarly with the physical side of physiologyv , and , of 
course, he does not need the microscope much. I know nothing of a 
pathologist, who handles a microscope well; here, I do not believe, 
that there is one.. l do not know really, what pathology means,. 
The microscopical cover-glasses you find in London at:C.M, 
Topping 4 New Winchester street, Pentonville Hill. London. I al- 
ways ^ret them from them, . The only fault of the man is, that he ne- 
ver sends a bili; and I have trouble payin/3* for them,, He makes 
quite good preparations. But, may-be. somebody eise in London 
makes better ones. Mr. Kippish. librarian of the Linneen Society 
will be able to give you information. When in London, I recomend 
