EFFUSION. 135 



towards organization. According to D'Arboval, ^^ sorts of 

 insulated portions of blood first make their appearance here 

 and there within it, in which are discoverable little straight 

 or flexuous canals, also filled with blood, terminating in 

 culs-de-sac, and having no communication with the vessels of 

 the pleura; from which, indeed, they are separated by a 

 layer of lymph. In a more advanced stage is to be observed 

 cellulo-fibrous layers, more or less dense, intersected through 

 their most consistent parts by a variable number of parallel, 

 rectilinear, and extremely slender vessels. At length the 

 time arrives for these vessels to unite with those of the pleura, 

 and from that hour the false membrane constitutes a part 

 of the integral structure.^^ 



In what space of time may, or ordinarily does, 

 EFFUSION TAKE PLACE ? — This is a qucstiou of vast importance 

 to the veterinarian. Disputes and horse-causes are so apt 

 to arise out of horses dying of pleurisy or pleuro-pneumonia, 

 wherein we are liable to be called upon for opinions, which, 

 if not received as decisive, must on all occasions be supposed 

 to have considerable influence in the decision, that it 

 becomes in us a bounden duty to make ourselves complete 

 masters of the subject in all its various relations. We are 

 requested to inspect the body of a dead horse — whom we 

 may have seen during life, or may not-— and we are sum- 

 moned before a jury to give evidence on oath concerning the 

 period of time such morbid alterations as may be presented 

 to us would take in forming; or, in other words, to say from 

 what antecedent date the commencement of the horse^s 

 disease is to be computed. This of all others is, perhaps, 

 a situation the most trying, the most responsible, the most 

 fearful, in which a veterinary surgeon can be placed. 



Referring to my own practice and personal observation, I 

 find, that, in one horse who died of a pleuritic attack in 

 seventeen hours after he was seized, there were recent 

 adhesions formed between the lungs and sides. In another 

 case it appeared sufficiently evident that three gallons of 

 water had become effused into the chest within three days. 

 From numerous experiments, however, which have been 



