90 BOVINE PATHOLOGY. 



corpuscles in all probability, and in addition have been 

 found to migrate through the walls of the capillaries into 

 the interspaces between the cells of which the tissues are 

 composed ; whether or not they thus nourish the tissues is 

 unknown. The blood of the ox has a specific gravity of 

 1060, and gives off a characteristic milky odour when 

 fresh, or when a little sulphuric acid is added to it. The 

 blood being circulated through the blood-vessels, mainly 

 by the action of the heart, requires for its proper functional 

 activity due bulk and viscidity and a proper chemical 

 composition. It must consist of the right constituents in 

 the right proportions. It may be excessively poor or rich 

 according to the conditions of its nutritive supply. It 

 may be irregularly distributed through the vessels as in 

 congestion with variations in rapidity of flow, and perhaps 

 of tissue interchanges. It is these latter which most 

 materially affect the composition of the blood. Every 

 tissue of the body bears during health the relation of an 

 excretory organ to. every other part ; by the combined 

 action of all the blood should be kept in a proper condi- 

 tion, its nutritive supplies being especially important. 

 The excretory organs proper have especially the duty of 

 removing impurities ; if one of them acts imperfectly the 

 rest may endeavour to atone for its deficiencies by vicarious 

 action, but they do not always do so successfully. Thus, 

 uraemic and jaundice cases occur. Sometimes poisons, 

 whether specific or ordinary, gain entry from without and 

 cause serious disorder. The blood being a generally 

 diffused tissue, we must look for general symptoms during 

 its disorders ; there v/ill be an indefiniteness and want of 

 localisation about them which to the unscientific man will 

 make them seem most obscure ; but we, armed with our 

 full list of haematics and eliminatives, view them with more 

 confidence. While the causes of blood disorders often lie 

 in defective nutrition or elimination, or in the addition of 

 poisonous matter from without, not unfrequently may 

 diseases of this generally diffused tissue be found due to 

 extension of disorder from some of the tissues through 

 which it rushes in its circulatory course. Thus may be 



