98 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Fig. 17. 



exudate and 1'5 ecin. of physiological salt solution be mixed in a narrow 

 test-tube (6-7 mm. diam.) and a drop of weak methylen-blue solution 

 added, the colour is discharged in a short while. The tube is closed 

 and placed in a thermostat. If, however, the leucocytes be damaged at 

 all by leucocides, heat, chiuin, &c, the fluid will remain more or less 

 blue, and the amount of damage may be roughly estimated from the 

 colour. 



New Method for Making Collodion Bags.* — Dr. M. A. Buffer and 

 Dr. M. Crendiropoulo describe a new procedure for obtaining the dif- 

 fusible poisons of micro-organisms in an ordinary culture tube. The 

 apparatus (fig. 17) consists of an ordinary test-tube A filled to any 

 required level with bouillon or some other fluid cultivating medium, 



and plugged with cotton wool at b. Through this 

 plug b is introduced another smaller glass tube a, 

 to the lower extremity of which is attached a col- 

 lodion sac d. This inner tube is filled to any 

 required level with some cultivating fluid, and is 

 plugged at the upper extremity e with cotton 

 wool. The collodion bag is made as follows : a 

 small test-tube is rapidly dipped bottom down- 

 wards into a vessel filled with collodion until 2 or 

 3 in. are covered with collodion. The layer is 

 allowed to dry, and then the process is repeated 

 twice or thrice. In order to free the collodion 

 from the tube, the whole is dipped alternately in 

 strong spirit and then into water. After a few 

 minutes the bag is loosened and can be slipped 

 off the tube. A small glass tube is then inserted 

 into the bag and the whole incubated at 37° C. 

 The bag is by this means shrunk firmly on to the 

 tube. In order to sterilise the collodion bag tube, 

 it is fixed in an empty test-tube in the manner 

 shown in the illustration, and the whole is steri- 

 lised at 150° C. by dry heat on one or several 

 occasions. When this has been done, the inner 

 tube a, together with the plug b, is transferred 

 aseptically to a tube of sterilised bouillon or 

 gelatin of equal size, the plug b now serving to 

 close the tube of bouillon into which the inner 

 tube is dipped. The bouillon in tube a is now 

 inoculated with the micro-organisms to be studied, and the whole placed 

 in the incubator. After a time the inner tube a is withdrawn ; the 

 outer tube contains the diffused products. This method may, of course, 

 be used for other purposes — for example, for testing the action of 

 microbes on fluids, or the antagonism of two different microbes. 



The Plague.f — It may be useful to mention that the British Medical 

 Journal for October 27, 1900, contains a series of original articles 

 dealing with the plague from its clinical, pathological, bacteriological, 



* Brit. Med. Journ., 1900, ii. pp. 1305-6 (1 fig.). 

 t Tom. cit., pp. 1229-58 (16 figs.). 



