454 Dr. W. Marcet on the Nutrition of 



while tliere is an increase of material to be eliminated, appa- 

 rently from a deficient action of that process which under normal 

 circumstances causes its removal. 



2nd. That the state of semifluidity in which tubercular lungs 

 are usually found after death, is attended with but a trifling in- 

 crease in the quantity of water beyond the proportion lungs 

 contain in health — water in the normal tissue amounting to 

 79*1 per cent., and in the diseased to a mean of 82*5 per cent. 

 At first sight this softening appears to be unacountable ; but on 

 a closer consideration the fact admits of an explanation. It 

 may be conceived that in the earlier stage of phthisis the 

 adenoid (tubercular) cells are held together by a colloid attrac- 

 tion, but that after a time, and under certain influences which 

 lower the vital power, this colloid attraction becomes lessened 

 and softening takes place. 



3rd. The relative proportions of effete phosphoric acid and 

 potash in the three analyses are very remarkable, as they are 

 found to be quite different from what they are in health. In the 

 normal condition, pulmonary tissue contains effete phosphoric acid 

 and potash in the proportion of 11 '32 to 88*68, there being a great 

 deal more potash than is necessary for the formation of a pyro- 

 phosphate ; and I explained how the removal of the potash could 

 be satisfactorily accounted for, by assuming that it was trans- 

 formed into a carbonate by the carbonic acid formed during the 

 process of respiration. Now as respiration cannot possibly take 

 place in tuberculosis where the pulmonary structure is altered, if 

 my view is correct we shall expect to find in the effete material of 

 tubercular lungs the proportion between the phosphoric acid and 

 potash materially changed ; indeed, as these substances must be 

 removed by a process of physical diffusion, we shall conclude that 

 their relative proportions must be such as to form a crystalloid 

 body. The mean relation obtained was. 



Phosphoric Acid . . . 47*7, 

 Potash .... 52-3, 



which approximates the formation of a pyrophosphate of potash, 



requiring 



Phosphoric Acid . . . 43, 

 Potash .... 47. 



I have therefore to point out the singular fact that consolidated 

 and softening lungs in phthisis undergo a process of nutrition 

 which appears to be closely allied to that of muscular tissue* 



Conclusions, 

 The conclusions I have arrived at from the inquiry which forms 

 the subject of the present paper may be summed up as follows : — 



