22 



self placed on a sheet of india-rubber cloth, and covering them with a bell- 

 glass. The air being soon saturated with moisture, the preparations cannot 

 dry. 



He then exhibited one of Mr. Lockhart Clarke's sections of the spinal 

 cord, and a single nerve-cell isolated and stained with carmine, prepared by 

 Qerlach, both of which were lent him by Dr. Dean, to whom they were pre- 

 sented by the distinguished anatomists of whose skill they are singularly per- 

 fect specimens. 



At the conclusion of Prof. Holmes's remarks, the orchestra furnished 

 music, the seats were removed from the hall, and an opportunity was given 

 to all to examine the various microscopes and objects under them. 



The objects were much varied in character. Dr. Holmes brought speci- 

 mens of the Pleurosigma angulatum, besides the sections made by Lockhart 

 Clarke and Gerlach mentioned above. Mr. Bicknell had several fine injected 

 sections of bones and teeth prepared by himself, as well as a large collection 

 of other objects, part of which he exhibited with a polarizer. Under Mr. 

 Webb's Binocular the head of a mosquito proved so attractive that no 

 time was found to exhibit but one or two other objects under his fine 

 instrument. Dr. Wilder had specimens of the silk of the Nephila plumipes, 

 and various parts of the spider. Mr. Sanborn exhibited a number of living 

 animalculce. 



Under the other microscopes were series of the pollen, and sections of 

 the leaf and stem of the Mayflower, Anemone, Bloodroot, Dogtooth Violet 

 and several other early spring flowers ; a large number of insects and parts 

 of insects ; Trichina spiralis ; sections of spines of echinoderms ; diatoms ; 

 &c., as well as several specimens of microscopical photography and engrav- 

 ing. 



The following is nearly a complete list of the microscopes that were in 

 the hall for use, arranged under the names of their owners. 



PBOF. O. W. HOLMES, of Boston. An instrument of his own construc- 

 tion, previously described. 



E. BICKNELL, of Boston. A large and very fine American instrument 

 made by Zentmayer, with Wales' objectives. 



DB. B. G. WILDER, of Boston. A Smith and Beck's Student's instru- 

 ment. ( Dr. Dean's working instrument ). 



F. G. SANBOBN, of Boston. The Mass. State Cabinet Nachet instru- 

 ment, of English form of stand with a lever stage. 



ESSEX INSTITUTE. A Prichard Standard microscrope, formerly owned 

 by Mr. Cole, and presented to the Institute several years since by Mrs. Cole. 

 An English instrument made by Clarke, presented to the Institute by Francis 

 Peabody, Esq.; also a French dissecting instrument made after Mr. Peabody's 

 plan and presented by him to the Institute. 



BENJAMIN WEBB, JR., of Salem. Smith and Beck's Binocular, Wen- 

 ham's invention ; and a Ladd's instrument. 



