1634 Journal of Applied Microscopy 



Ramsay. The Scientific Roll of Bacteria. R. An extremely useful publication for 

 L. Sharland, Churchfield Road, Acton, Lon- bacteriologists is this Scientific Roll of 

 don, W. ^ 



bacteriological literature. It aims to 



be a complete list of bacteriological papers, the title and place of publication 

 being given in all cases. The three numbers now issued comprise numerous 

 publications, from the early ones of Leuwenhoek, in 1680, to the end of the year 

 1901. The Roll is a regular publication and invaluable to bacteriologists. The 

 compilist invites the aid of all bacteriologists in making the list complete, by 

 sending him titles of all bacteriological papers, and reprints where possible. 

 His address is, Alexander Ramsay, 4 Cowper Road, Acton, London, W. 



H. w. c. 



Widal and Ravaut. Cytodiagnosis. Interna- Cytodiagnosis consists in determining 

 tional Congress at Paris, looo. ^, ^ - ^, • i- ■ i i .i 



° the nature of a pathogenic liquid by the 



study of the cells it contains. Widal and Ravaut have given the results of their 



researches at the Societe de Biologie and the Societe' Medicale des Hospitaux. 



The following is their method : 



A few centimeters of liquid is sufficient for the examination. If the liquid 

 shows no coagulum it can be examined direct, but if coagulated it must be shaken 

 with glass beads, and, if very turbid, it is decanted to avoid the fibrin, and then 

 centrifuged. 



The examination can be made without staining, and it is easy to count the 

 corpuscles, and even the leucocytes between the desquamatous epithelial cells. 

 For this purpose a hematometer may be used, care being taken not to dilute 

 the material too much. It is useful to count the number of both red and white 

 corpuscles in a cubic millimeter. It is necessary also to study a stained speci- 

 men. A drop of the residue from the centrifuge is placed upon a slide with a 

 pipette, and stained with thionine, eosin, hemateine or triacide.* The material 

 is fixed, preferably by alcoholic-ether if they are to be stained with thionine, 

 eosin or hemateine, but in toluene at llO'^C. if they are to be colored in triacide. 

 The preparations may also be dried in a drying oven for a proper length of 

 time, and then fixed with absolute alcohol. 



Pathogenic liquids exuded from the pleural or abdominal cavities, from the 

 vagina and testis, from the joints and the subarachnoid space, have been exam- 

 ined by different observers by the method of Widal and Ravaut. A large num- 

 ber of important results have been obtained from the work. 



Sero fibrous streptococcic pleurisy is characterized almost exclusively by the 

 presence of polynuclear leucocytes ; pneumococcic pleurisy by red corpuscles, 

 and some lymphocytes, but always by polynuclear leucocytes, and a greater or 

 smaller number of mononuclear leucocytes, of which some are true phagocytes 

 which engulf the polynuclear cells in their protoplasm. 



Pleurisy "a frigore," which is commonly of tuberculous nature, produces a 

 discharge of lymphocytes. Mechanical pleurisy of the heart shows liquids filled 

 with red corpuscles and few lymphocytes. Its chief characteristic is the pres- 

 ence of large cells, like the endothelial cells which are separated from the pleural 

 surfaces. 



The study of hydrocele liquids and those from the chord and brain have 

 given results of great interest. Chronic diseases of the nervous system can be 

 studied by this method with equal advantage. 



From these examples it may be seen that the method is both novel and useful. 



A. GiRAULD, Translated by H. W. C. 



*I do not know these stains and give the French word. 



