586 PRACTICE OF PHYSIC. 



spiration, there is one mark which is much more decisive in 

 pointing out the debility of the system, that is, a change of the 

 tone of voice. This indeed almost always depends upon the 

 state of the muscles of the glottis ; it is properly an animal 

 function, and is not necessarily connected with the vital, but 

 the consideration of the respiration brings it especially to our 

 minds. It is observed, that it is among the first marks of sick- 

 ness attended with debility. This change in the tone of the voice 

 goes on through various degrees till it amounts to an aphonia ; 

 and the common people of this country mention it as a sure mark 

 of approaching death, that the patient is past speaking. I find 

 some difficulty in explaining this ; but I may observe, that how- 

 ever the formation of the voice is to be explained, it depends upon 

 the muscles which move the membranes that form the glottis, 

 and the cartilages with which those membranes are connected. 

 Whether the voice is formed merely by the contraction of the 

 parts concerned, our thorax being in that respect a wind instru- 

 ment, or whether it depends on the different degrees of tension, 

 according to the late and now common opinion, I would not 

 determine here ; but it is certain that it depends upon some ex- 

 quisitely nice and minute motions, which, like those of the eye 

 and tongue, are first affected in fever ; whether this change of 

 the voice proceeds from a diminution of the tension, or of the 

 aperture, we can see that it is a very proper mark of the state 

 of debility in the system. So much with respect to the case of 

 debility as the symptoms of it occur hi the vital functions, and 

 what is immediately related to them." 



" C. The marks of debility in the Natural Functions ; and, 

 First, as it appears in the Appetite and state of the stomach. 

 Here the debility is in very different degrees ; as it appears in 

 the anorexia or want of appetite ; in a manifest aversion to food ; 

 or still further, as that amounts to a nausea, which, when a little 

 increased, frequently arises to actual vomiting. The symptoms, 

 then, I speak of, are, anorexia, nausea, and vomiting. I for- 

 merly (XLIV.) explained upon what grounds all of these 

 may be considered as marks of debility, and how they ^generally 

 appear more or less in proportion to the other marks of debility 

 prevailing in the system ; at the same time, I observed that 

 they are in a particular manner connected with the state of the 



