14 INOCULATION AS A PREVENTION OF PLEUEO-PNEUMONIA. 



in modern agriculture to place farmers in a position where they 

 cannot profitably make use of natural grasses for enriching the 

 soil. It may be asked if land is valued upon a sound basis at 

 the present time ? I leave this question for the consideration of 

 those more immediately concerned, and shall conclude this essay 

 by giving it as my opinion that the most urgent thing for those 

 connected with the management of arable land is that those 

 acquainted with chemistry should come to an early understanding 

 as to what the first and fundamental principle in agriculture is. 

 If this were clearly defined, the different opinions at present pre- 

 vailing about carrviocr out of details would lose much of their 

 present importance, and more attention would be given to the 

 profitable application of capital to the soil. 



Since this essay was put into the hands of The Highland and 

 Agricultural Society last year, and subsequent to several allusions 

 made to the subject of the essay in the public prints, Dr. Lawes 

 issued a pamphlet which contained the following paragraph, 

 namely : — 



" Instead of regarding the operations of draining, fallows, 

 liming, tillage, and the use of mineral manures as so many ways 

 of increasing the stock of fertility, they would be more correctly 

 described as processes for turning to account the existing but 

 dormant elements of fertility contained in the land. They 

 increase the produce, but at the expense of the stock of fertility 

 in the soil." 



INOCULATION AS A PREVENTION OF PLEURO- 

 PNEUMONIA. 



By R. Rutherford, V.S., Edinburgh. 



[Premium — Ten Sovereigns.'} 



In considering the value of the practice of inoculation for the pre- 

 vention of that malady in cattle known as " Contagious Pleuro- 

 pneumonia," it would seem to me to be advisible to do so from 

 two points of view, a scientific and an economic, the latter especi- 

 ally, — for it is not only necessary that the operation be sound in 

 principle, it must be practicable to be of value at all, and must 

 in results, favourable or otherwise, be able to bear the crucial 

 test of comparison between it and any other mode of dealing 

 with the disease. How far inoculation can answer these require- 

 ments I shall endeavour to show. 



The practice of inoculation for the prevention of pleuro- 

 pneumonia is now about thirty years old. It is based upon the 

 now generally accepted theory of the disease being an eruptive 

 fever, one of a group, some of which are common to man and 

 some to the lower animals. Or to put it more plainly, pleuro- 



