M.— AGRICULTURE. 237 



Another disease which at one time was responsible for very serious 

 losses and which has now practically disappeared, is Pleuro-pneumonia 

 (Lungsickness) of cattle. In the year 1860 about 187,000 head of cattle 

 are stated to have died in Great Britain of this disease ; and the mortality 

 in other European countries at that time was correspondingly high. 

 Towards the end of last century the disease was stamped out in Britain 

 and to-day the greater part of Europe is free of the disease. It may be 

 added that South Africa, in spite of the fact that neighbouring countries 

 are still infected, has been free of Lungsickness since 1915. 



Anthrax is almost universal in its occurrence, but it is much more 

 formidable in the tropics and sub-tropics than in the colder countries of 

 Europe. In the latter countries it appears in sporadic cases, whereas in 

 the former it behaves like any epizootic disease. For this reason its 

 suppression in these countries becomes a matter of great urgency. The 

 problem has been tackled on a big scale in Australia and South Africa by 

 means of preventive inoculation. In the former country the disease has 

 nearly been stamped out, and in South Africa the campaign is carried on 

 with great vigour. The excellent results obtained with the spore vaccine, 

 now employed, promise complete success. 



The position in the warm countries in regard to Quarter Evil {Black 

 Quarter) is much the same as with Anthrax. The disease appears almost 

 in epizootic form and preventive inoculation on a large scale becomes 

 necessary. Very satisfactory results have been obtained in South Africa 

 both with a germ-free filtrate and with a formalised vaccine. 



Only one other bacterial disease can be mentioned here, namely. 

 Tuberculosis. In 1901, Robert Koch, who about 20 years previously had 

 discovered the cause of the disease, startled the scientific world by 

 announcing to a Tuberculosis Congress in London that human tuberculosis 

 and bovine tuberculosis were two distinct diseases which were not com- 

 municable from the one species to the other. Unfortunately, this statement 

 proved to be wrong. We know to-day that human beings do contract 

 bovine tuberculosis, and for this reason most civilised countries adopt 

 measures for the suppression of the disease in cattle. The United States 

 and Canada are leading the world in this respect and have spent millions 

 of pounds in compensation for the destruction of tuberculous reactors. 

 Denmark, Germany, England and other countries are also doing 

 much and have achieved a large measure of success in their efforts 

 to supply to the population milk and beef free of tubercle bacilli. 

 But very much remains to be done. In human beings the mortality 

 from tuberculosis is still high in all countries, and a considerable 

 percentage of the deaths must be ascribed to the bovine strain of the 

 organism. The disease in cattle can be stamped out provided enough 

 money is made available. 



Recently great interest has been shown in the attenuated strain of 

 tubercle bacilli produced by Calmette and Guerin of the Pasteur Institute. 

 Experiments in which it is attempted to immunise children and young 

 animals, with this strain, are in progress throughout the world. It is 

 sincerely hoped that all this work will prove that the method of Calmette 

 and Guerin has given us yet another weapon against this insidious 

 disease. 



