HYDROTHORAX. 141 



cate^ composed of loose filaments, crossing one another in 

 every direction, and forming a transparent tissue, bearing 

 the closest analogy to the woof of lace. The areolae, close 

 together, and hardly perceptible in the young subject, grow 

 larger with age, and soon render visible, here and there, a 

 multitude of either round or irregular apertures, which 

 establish a direct communication between the two pleural 

 sacs. This is a peculiarity important to become acquainted 

 with. It explains the gravity of chest-effusions in horses ; 

 it renders obscure and difficult of distinction the side affected 

 in pleurisy, since the fluid runs from one cavity to the other, 

 and thus gives rise to double hydrothorax. It is certainly 

 possible for the fluid to pass through the natural openings, 

 enlarged, of the mediastinum ; but Delafond has discovered 

 in eleven cases of pleurisy, that, in fact, there was a rupture 

 of this frail partition. The same skilful veterinarian has 

 remarked, however, that this communication is not invariably 

 present, although there may be effusion in both pleural sacs. 

 He has twice found it wanting. 



The TREATMENT OF HYDROTHORAX is au affair of despera- 

 tion. We have more chance of succeeding in attempts to 

 prevent than to remove it : we must, therefore, endeavour to 

 check the disposition, and avert the secretion. We must 

 not suffer inflammatory action, however apparently trifling 

 in degree, to lurk about the chest; but by continued medi- 

 cinal and derivative measures persist in our efforts to subdue 

 it, or to translate it to parts where it cannot do the same harm. 

 In sub-acute and chronic pectoral affections, which, I repeat, 

 are especially likely to end in effusion of water, we must con- 

 tinue to push the Plummer^s ball : our principal object being 

 now, more than ever, to increase the action of the several 

 emunctories of the body — the kidneys, the skin, the salivary 

 organs, &c. Gohier speaks in high terms of cantharides 

 as a remedy for incipient hydrothorax. Knowing its active 

 diuretic properties, I have often been induced to give it in 

 cases of dropsy, and, I think, with advantage; but not in 

 the large doses. Gohier gives from a drachm {gros^) to a 

 ' A gros is equal to 3'82 grammes, of 15*348 grains troy, eacli. 



