1884.] 



MICROSCOPICAL JOURNAL. 



31 



zinc. The writer once made a "white 

 zinc cement which has stood the test 

 of years, but it was made with shellac 

 as a basis. 



For a black finish for mounts there 

 is nothing superior to the asphalt, or 

 Brunswick black sold by the opticians. 

 We do not commend this as a cement, 

 but only as a brilliant, black finish for 

 mounts. One of the best mixtures 

 that can be devised is composed of 

 equal parts of asphalt and gold-size. 

 We shall have frequent occasion to 

 refer to it in the course of these arti- 

 cles. Gold-size is frequently used 

 alone as a ceinent, and for making 

 rings on slides for mounting. It is a 

 great favorite w^ith some persons, but 

 we do not advise its use. 



Having thus briefly alluded to the 

 inaterials required for mounting, the 

 more interesting part of the subject 

 will be opened next month, when the 

 different kinds of mounting vs^ill be 

 discussed, and some hints given to 

 enable the beginner to choose the 

 proper method for preserving any 

 specimen. 



The following list of articles that 

 should be obtained will be of assist- 

 ance to those readers w^ho may desire 

 to have all the essentials for mounting 

 at hand^ It includes all the articles 

 mentioned above, and a few others : — 



APPARATUS. 



Spirit lamp. 



Brass mounting table. 



Mounted needles. 



Small surgeon's scissors. 



Small surgeon's knife. 



Steel forceps, straight and curved. 



Brass forceps, curved. 



Dipping tubes and rods. 



Medicine droppers, |- doz. 



Bullets for weights. 



Curtain rings for f and f covers. 



Turn-table. 



Gun-punches, | and |-inch, for cut- 

 ting wax. 



Cover-glasses, No. 2 round, diame- 

 ters f , |, and l^-inch. 



MOUNTING MEDIA AND CEMENTS. 



Alcoholic shellac. 

 Bell's cement. 



Canada balsam. 



Canada balsam in benzole or chloro- 

 form. 



Damar medium. 

 Sheets of dark olive wax. 

 Glycerin jelly. 

 Brunswick black. 

 Gold-size. 



Carbolic acid, crystallized. 

 Pure glycerin. 

 Alcohol. 

 Turpentine. 



Oil of cajaput or eucalyptus oil. 

 o 



New Method of Detecting Trichina 

 in Meat.* 



Slices, two or three millimetres in 

 thickness, are taken from several dif- 

 ferent pails of the meat to be exam- 

 ined. The pieces are preferably taken 

 from the surface of the muscular por- 

 tion of the ineat. A series of thin 

 sections are made of each of the 

 pieces, and these are all plunged into 

 a solution coinposed of methyl green i 

 gramme, distilled v^^ater 30 grammes. 

 After about ten minutes' maceration 

 the sections are taken out, and placed 

 to decolorize in a large vessel filled 

 with distilled water. They remain 

 there about half an hour, the w^ater 

 being agitated and changed two or 

 three times. Finally, the water hav- 

 ing become quite limpid, it is stirred 

 up with a glass rod, interposing the 

 vessel between the eye and the light, 

 when the sections containing the 

 trichinae are distinguished quite read- 

 ily with the naked eye. The trichi- 

 nae appear in the form of small, elon- 

 gated particles, of a fine blue color. 

 The methyl green becomes fixed to 

 the cysts of the trichinae with greater 

 tenacity than to the other parts of the 

 tissue. 



It suffices then to examine the sec- 

 tions with a magnification of fifty dia- 

 meters to distinguish the worm which 

 will be found enclosed in the cyst. 



If, in following this method, no 

 trichinjB are found, it is positive as- 

 surance that the meat is not infested 

 with them. 



* Bull, de la Soc. Beige de Micr. 



