SPIRILLUM AND SPLENIC FEVEE. 749 



remarkable fever ; the chief interest in which centres 

 in the fact that the specific organisms which induce 

 it are bacteria. Splenic fever attacks horses, cattle, 

 sheep, rodents, and even man ; it covers a wide range 

 of country, extending over Europe, Asia, and Africa. 

 In Russia, it is known as Siberian plague ; in India, 

 as the Pali plague ; in Germany and Austria, where 

 it is endemic as well as epidemic, as Milzbrand. In 

 Zululand it was the cause of an enormous loss of 

 horses, as many as fifty per cent, a week dying from 

 the fever. The algoid, rod-like bodies discovered in the 

 blood are from the 1 -20,000th to the 1 -40,000th of an 

 inch in diameter. When acted upon by a fluid of less 

 density than blood, and near to the commencement of 

 the putrefactive process, they break up into spheroids, 

 each with a slightly darker spot or nucleus in the centre. 

 A striking feature of the disease is its very rapid pro- 

 gress. An animal is observed to refuse its food, this 

 is followed by a shudder, a convulsive or apoplectic fit, 

 and in the course of a few hours it will be dead. The 

 symptoms are accounted for by the rapidity of multi- 

 plication of bacteria in the blood. 



For the preservation of bacteria Koch's method is 

 the best. It consists in drying the liquid containing 

 the bacteria in a very thin layer upon slips of glass, 

 so as to fix the bacteria in a plane, treating this layer 

 with the colouring material, and then again moistening 

 it to restore the bacteria to their natural form and make 

 them distinctly perceptible, so that the preparation may 

 be enclosed in a preservative liquid and finally mounted 

 in glycerine. Glass slips with dried bacteria last for a 

 long time, and can be transmitted by post. For the 

 moistening of the layer Koch uses a solution of one 

 part of acetate of potash in two of water. In this 

 solution the bacteria assume their original form without 

 becoming loosened from the glass. For colouring he 

 uses a mixture of a few drops of a concentrated spirit- 

 ous solution of fuschin or methyl violet with 15 to 30 

 grams of water. Preparations so coloured may be 

 mounted in concentrated solution of acetate of potash 

 or in Canada balsam. 



