THF, RABBIT-PLAGUE IN AUSTRALIA. 93 



" The loss, and even desolation, caused in many parts of this 

 county by the excessive multiplication of Rabbits, and the great 

 reward of .£25,000 offered by New South Wales for their extirpa- 

 tion, have induced many efforts to discover a cure for the plague. 



" Of these the most important has been that of M. Pasteur ; 

 but his proposed remedy is so uncertain, and at the same time 

 contains such elements of danger, that I have thought it right, as 

 a matter of urgency, to direct the attention of the Royal Society 

 to the subject. 



"He has discovered that a certain virulent epidemic disease, 

 found in France and parts of the Continent, and called the * fowl 

 cholera,' can be easily communicated to Rabbits, and with fatal 

 effect. The poison of this disease he intends to scatter broad- 

 cast throughout the colonies, hoping in this manner to destroy 

 the Rabbits everywhere. 



" It is this scheme, the prospects of its success, and the grave 

 risks attending it, that we have to consider. 



" His plan is to obtain the microbe, which is the effective 

 cause of the disease; to cultivate it in properly prepared infu- 

 sions, until he has multiplied each single particle of the poison 

 into hundreds of millions, and then to spread it over the ground, 

 or over food prepared for the Rabbits. The microbe is a living 

 being, extremely minute, and found in the blood of diseased 

 animals ; and it is supposed that there is a special one for each 

 form of disease. There is much difficulty in saying whether it is 

 vegetable or animal. 



" It is now nearly forty years since microbes were first 

 noticed by Davaine, but their real importance as factors in 

 disease was not recognised thoroughly until 1877, when the cele- 

 brated paper of MM. Pasteur and Joubert was read before the 

 Academy of Sciences. 



" These gentlemen selected anthrax, a disease affecting men 

 and cattle, called in the first case ' malignant pustule,' and in 

 the second ' splenic fever,' and showed that in the blood myriads 

 of these little organisms were found, either as slender waving 

 rods, or minute oval spores, or as curled filaments ; and also 

 proved that the poison, if it existed in these, could be cultivated 

 out of the body to an indefinite extent, without losing any of its 

 infectious virulence. The method was this : — A neutralised 

 decoction of yeast in water was strained and heated so that all 



