90 DISEASES OF THE LUNGS. 



tion during inspiration and expiration : observation, however, proves that 

 this is not always the case— that in fact, these signs become manifest only 

 in certain states, as will be seen hereafter. We find an exposition of 

 these symptoms in a case of hydrothorax published by M. Massot, which 

 he recovered by tapping. "When the ear is applied," says he, "beneath 

 the sternum, a dull, confused, drawling sound is heard, something similar 

 to the noise made by rolling a cask containing liquid." This observation 

 is confirmed by M. Dandrieu, in a case of carditis, with water in the peri- 

 cardium of a cow, narrated by him in the ' Receuil de Medecine Veteri- 

 naire,' vol. iii, p. 488. "I applied," observes M. Dandrieu, "my ear 

 against the left side of the thorax, and I heard a slight confused noise, 

 which I presumed to be caused by a fluid already partly effused into the 

 cavity of the pleura, and, perhaps, even into the pericardium." M. 

 Leblanc seems to confirm both these accounts, when he says, in speaking 

 of pleural sounds, that " at one time, kinds of rumbling (as of the bowels) 

 are heard; at another, spumous sounds, if I may so express myself; at a 

 third time, a gurgling sound : the first and last are ordinarily heard 

 towards the lower part of the chest, supposing effusion to have taken 

 place. 



Experience has convinced me that the presence of fluid cannot with 

 certainty be made out by these signs, except under two circumstances : — 

 1st, when false membranes have been recently formed; 2dly, whenever 

 gas becomes mingled with the fluid : whether it be generated by the fluid 

 itself, be exhaled hy the pleura^ or get accidental admission into the cavity, 

 the result is, that agitation produces froth; and then the spumous rale, 

 combined with rumbling, becomes audible at the bottom of the thorax, 

 and the less the quantity of fluid the louder the noise. Should there 

 exist both fluid and false membranes, the sound becomes modified, ap- 

 proaching to rumbling, or rather to the gurgling of a bottle emptying 

 itself while its neck is full, but much more feeble. This noise has always 

 appeared to us to ensue whenever, with the effusion, there were present 

 false membranes which had so formed or arranged themselves as to have 

 small areolce^ or cavities of various capacities, into which the fluid entered 

 during the act of respiration. In every case of hydrothorax without false 

 membranes, and the presence of gas in the cavity, that has come under 

 our observation, even when the like was produced by the injection of 

 warm water into the chest, with the precaution to suffer the admission of 

 as little air as possible, we have on no occasion heai^d any sound produced 

 hy the fluid. Moreover, it has long been an established fact in human medi- 

 cine, that no sense of fluctuation, either by succussion or by auscultation, 

 is detectable, except when gaseous fluid is mingled with the liquid efi"used: 

 a case, be it remarked, extremely rare. 



Such are the sounds afforded by the respiratory organs in horses : those 

 of men furnish still more on account of the voice, which the surgeon having 



