534 PRACTICE OF PHYSIC. 



be observed, that in it there is a degree of torpor in the motion 

 of the nervous power, both with respect to sensation and voli- 

 tion ; that there is a general rigidity of the simple solids ; and 

 that the balance of the sanguiferous system is upon the side of 

 the veins. But all these circumstances are the directly opposite 

 of those of the sanguine temperament ; and must therefore also 

 produce an opposite state of mind. 



MDXC. It is this state of the mind, and the state of the 

 brain corresponding to it, that is the chief object of our present 

 consideration. But what that state of the brain is, will be sup- 

 posed to be difficult to explain ; and it may perhaps seem rash 

 in me to attempt it. 



I will, however, venture to say, that it is probable the melan- 

 cholic temperament of mind depends upon a drier and firmer 

 texture in the medullary substance of the brain ; and that this, 

 perhaps, proceeds from a certain want of fluid in that substance, 

 which appears from its being of a lesser specific gravity than 

 usual. That this state of the brain in melancholia does actual- 

 ly exist, I conclude, t first, from the general rigidity of the whole 

 habit ; and, secondly, from dissections, showing such a state of 

 the brain to have taken place in mania, which is often no other 

 than a higher degree of melancholia. It does not appear to me 

 anywise difficult to suppose, that the same state of the brain 

 may in a moderate degree give melancholia, and in a higher, 

 that mania which melancholia so often passes into ; especially, 

 if I shall be allowed further to suppose, that either a greater 

 degree of firmness in the substance of the brain may render it 

 susceptible of a higher degree of excitement, or that one portion 

 of the brain may be liable to acquire a greater firmness than 

 others, and consequently give occasion to that inequality of ex- 

 citement upon which mania so much depends. 



MDXC I. I have thus endeavoured to deliver what appears 

 to me most probable with respect to the proximate cause of 

 melancholia ; and although the matter should in some respects 

 remain doubtful, I am well persuaded that these observations 

 may often be employed to direct our practice in this disease, as 

 I shall now endeavour to show. 



MDXCII. In most of the instances of melancholia, the 

 mind is to be managed very much in the same manner as I 



