ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 507 



noxious fumes from boiling acids are avoided. The process was originally- 

 suggested by Mr. G. C. Morris, of Philadelpbia ; be, bowever, suggested 

 tbe use of a platinum crucible, which is costly. The porcelain gallipot 

 answers every purpose, while the expense is merely nominal. 



Preparing Bacterial Material for Transmission by Post.* — Dr. G-. 

 Marzi has devised the following method for transmitting specimens of 

 bacterial material by post, &c. 



Square pieces of gelatin leaf, about 14 mm. broad by 25 mm. long, are 

 soaked for five minutes in a 1 per cent, solution of sublimate in absolute 

 alcohol. These having been repeatedly washed in alcuhol, are placed under 

 a sterilized bell-jar to dry. A small quantity of the bacterial material (a 

 pure cultivation, blood serum or the like) is then spread with a platinum 

 wire on the gelatin leaf near the edge. When the preparation is quite dry 

 it is rolled in sterilized tinfoil, put in a case and labelled. Two specimens 

 should be sent, one for microscopical examination, the other for cultivation. 



The receiver, after having unrolled the tinfoil, rubs the gelatin disc on 

 the surface of a cover-glass moistened with sterilized water. To the cover, 

 the greater part of the bacterial material adheres, and can be used at once 

 after staining, for microscopical examination or for cultivation purposes. 



If it be certain that the culture be pure and that the microbes are alive, 

 the second specimen can be used for cultivation on gelatin ; if not perfectly 

 pure, the isolation method must be adopted. 



Technical Method of Diagnosing Gonococci-t — M. G. Eoux recommends 

 the following method of determining the absence or presence of the 

 Gonococcus of Neisser, which has hitherto been very difficult. When it is 

 attempted to detect micro-organisms in any organic liquid, the method 

 of double coloration of Gram is generally adopted, that is, after the prepara- 

 tion has been dried and stained by methyl-blue or gentian-violet, it must be 

 submitted to the iodized iodine liquid of Gram, which possesses the property 

 of fixing the anilin colours on the microbes exclusively ; the preparation is 

 then decolorized by alcohol, treated with distilled water, and re-stained with 

 eosin ; although this method generally succeeds with secretions, it always 

 gives a negative result if Gonococcus alone is present. In doubtful cases, 

 then, if Gonococci have been recognized on staining by gentian-violet or 

 other reagent without the addition of alcohol, it is only necessary to adopt 

 the method of Gram; if, then, all the cocci disappear they are those of 

 Neisser ; if, on the contrary, they or any remain, there must be doubt as to 

 the blennorhagic nature of the secretion. 



Preparing Crystals of Salicine.i — Dr. F. L. James writes as follows : — 

 " Some years ago the writer, after finishing a lot of slides of various 

 crystals for examination under the Microscope, poured a few droj)s of a 

 solution of salicine on a piece of window glass, and left them to crystallize. 

 Some days afterwards, on examining the glass, he was surprised and de- 

 lighted at the gorgeous beauty of the crystals. Two of the drops had 

 crystallized so that the glass could be cut away into slides and mounted. 

 These two specimens have been shown annually at the meetings of the 

 American Society of Microscopists, and have been seen and admired by 

 thousands, not one of whom had ever seen their equal. Words utterly fail 

 to give any idea of their splendour. 'Nothing,' said a gentleman at 

 Cleveland, ' short of the Pearly Gates can compare with them.' 



Although during the past four or five years I and my students 



* Eiforma Medica, 1886, No. 21. 



+ Comptes Kendus, ciii. (1887) pp. 899-900. 



+ St. Louis Med. and Chirurg. Jotun., li. (1886) pp. 280-1. 



2 L 2 



