1893.J MICROSC'OPK'AL JOURNAL. 263 



knowledfje. It contains a tar larger nuinl)er of words than any 

 other one-vohnne nicclical lexicon. 



Not\vithst;indin<j the larj^e outlay necessary to its production 

 on such an elaborate plan, the price will be no higher than usual. 



LKTPKRS TO THE EDITOR. 



Note. — This tohnun is open to all correspoiidrtils -v/io zvri/r upon the 

 topics ennmeratvd under " Problems,'^ or v: ho give olher in formal ion of 

 interest. The fact that a problem has been anszvend once need not deter our 

 friends from ma king additional comments. To facilitate reference, corre- 

 spondents should cite the number as zvell as the pa^e on zvhich have ap- 

 peared letters and tjueries to tvhich reference is made. The editor is not 

 responsible for tie vieivs of others published in this periodical. 



The Microscopical Preparations of M. Bourgogne. — A box 

 of slides recently received from tliis eminent l\iris artist merits 

 more than a passing word of commendation. The slides pos- 

 sess the merit of cleanliness, (something not always found in the 

 work of alleged professional i)reparers in this country), and 

 the cell finish is neat, smooth and i)lain. Butthis latter feature 

 is a secondary matter, of course, and that which is under the 

 cover glass is the ultimate test. I can only say that the work of 

 M. Bourgogne is as near perfection as is reasonable to expect 

 in human handiwork. I will take space only to speak of two 

 preparations, where all are good. One is a section through the 

 head of the blow fly, Musca vomitoria, taken at such a point as 

 not only to show a section of the brain but through the optic 

 nerves to each eye and including sections of the eyes themselves. 

 The other pre])aration is arranged under a large oval cover glass, 

 and consists of three translucent leaves of the Evergreen Box ; 

 BuxHS sempervlrens. One leaf is prepared to show the veining, 

 the other two different layers of structure. In addition, on 

 either side of one of the leaves is arranged artistically three 

 transverse sections of another leaf of the same plant. 



The slides are not only objects of art for the cabinet but are 

 a continual incentive to l)e satisfied with nothing short of the 

 best work in one's own individual attempts at mounting. — A. 

 L. Woodward. 



MICROSCOPICAL APPARATUS. 



Cedar- W^ood Oil. — This oil possesses a growing importance 

 in connection with its use with optical instruments. For this 



