The Mickoscope. 317 



Phosphorescent Bacteria. — The property possessed by certain 

 sea-lish, of being phosphorescent in the dark, is due to the presence 

 on their surface, of micro-organisms, living there as parasites. 

 These are short, oblong bacilli, easily isolated by Koch's method. 

 They develop on gelatine which they do not liquify, if from two to 

 three per cent, of common salt be added. They form excessively 

 curious luminous colonies. By exposing the cultures to a tempera- 

 ture of 35^^ to 37° Centigrade, they soon lose their vital properties, 

 and their serial reproduction becomes impossible. On the other 

 hand, at a temperature of freezing they develop with manifest rapid- 

 ity. (W. Q^llinger, Revue des Sciences Medicales.) 



Microscopy of the United States Phabmacopceia.— In a recent 

 paper by Prof. H. M. Whelpley, of St. Louis, the writer says : 

 " The sixth decennial revision of the United States Pharmacopoeia 

 does not have much to say about the microscope, although the 

 instrument is recognized more than it was in the previous revision. 

 Among the eighteen principles adopted at the national convention 

 for the guidance of the revision committee, we find the fifth to read 

 as follows : 



" ' Description of Crude Drugs. — To all crude drugs of animal 

 or vegetable origin, concise, but complete, descriptions are to be 

 added, sufficient to indicate the physical characteristics visible to the 

 naked eye, and, when necessary, such as are visible under an ordi- 

 nary good pocket lense, magnifying about ten diameters. When 

 external and visible properties are insuificient to characterize the 

 substance properly (as in the case of gums, resins, balsams, etc.), it 

 shall be further defined by the physical and chemical properties.' 



"The following is a list of drugs of which the committee saw fit 

 to mention the microscopic structure: Aconitum, anisum, apocy- 

 num, arnica radix, asclepias, aspidium, azedarach, bryonia, buchu, 

 calamus, carum, cimicifuga, cinchona flava, cinchona rubra, conium, 

 coriandrum, dulcamara, foeniculum, gelsemium, geranium, glycyr- 

 rhiza, haematoxylon, inula, jalapa, juniperus, krameria, lappa, menis- 

 permum, pareira, phytolacca radix, podophyllum, pyrethrum, quassia, 

 quillaia, rheum, rumex, sanguinaria, sarsaparilla, senega, stillingia, 

 sumbul, taraxacum and zingiber. 



" In addition the above list of drugs, the following preparations 

 come under the same rules for descriptions: Hydrargyrum cum 

 creta, m'xssa hydrargyri. In this case the microscope is employed 

 negatively to prove the absence in place of presence of certain char- 

 acteristics. A microscope whose magnifying power is limited to ten 



