18 



In quiet cattle, again, a veterinary surgeon or person accus- 

 tomed to examine this class of cattle will be able by auscultation 

 and percussion to pick out the right subject, if any of them are 

 affected. 



If the selection is a correct one, very little of the lung will be 

 firmly hepatized, and none of it should be dark or mortified-looking ; 

 but while a portion of it has only reached the inflamed or con- 

 gested stage, there will be found a soft jelly-like part which has 

 quite recently become hepatized, and is plainly charged with 

 quantities of lymph — i.e., clear virus. The part indicated will be 

 known also by the comparatively bright light colour and fleshy 

 appearance of the brown portion of the hepatization or marbling. 

 This is the part to be iised, and the virus when extracted should 

 have but a very slight tinge of blood. The part of the lung thus 

 selected is to be placed in an earthenware dish, and to be 

 cut up in small pieces, when the greater portion of the virus will 

 flow from the lung and can be poured off". The pieces may then 

 be put into a cloth of open texture, and the virus still remaining 

 in the lung gently expressed from it. The operation of collecting 

 the virus should be carried out in as cool a place and the virus 

 exposed to the air as little as possible. The whole virus thus 

 obtained should be filtered through a piece of fine muslin into a 

 clean bottle in the first instance, and then through a thin layer of 

 powdered charcoal. This is the plan adopted by the best 

 authorities in Germany, and it has only to be mentioned to 

 recommend itself to those who iutend to perform the operation, 

 as they ought to do, with nicety and care. 



Lymph or matter taken from the part inoculated after it has 

 assumed a sort of pustulous head has been found to be fully as 

 active and apparently as effective as virus taken from the diseased 

 lung ; but the quantity of lymph procurable in this way is com- 

 paratively small, and only eno\igh to operate on a few head, even 

 when a great many cattle have been inoculated. Sufficient virus 

 or lymph could therefore, never be procured in this way to inocu- 

 late a herd of bush cattle. 



Virus taken from the neioly liepatized -portion of a lung in a too 

 advanced — the iMrd stage of the disease — has been used with 

 good eftect so far as the protection of stock inoculated is con- 

 cerned ; but a very much larger percentage of excessive and 

 dangerous swellings are certain to result from the use of such 

 virus than when it is taken from a lung in the right stage of the 

 disease, and it should never be used unless where it is impossible 

 to obtain the right sort of lung. 



Some owners, again, have inoculated with the serous fluid found 

 in the cavity of the chest, in cases of hydrothorax — the wet form 

 of the disease. As, however, hydrothorax is more properly a 

 sequence than a stage of pleuro -pneumonia, and as hydrothorax 



