280 



Miss D. J. Lloyd. 



results of experiments on the degree of swelling in the different solutions 

 are given in fig. 2. It will be noticed that the degree varies according to 



-r *oo 



Abscissae = negative logarithm of hydrogen ion concentration. 

 Ordinates = final weights expressed in percentages of initial weights. 



I = curve in HC1 ; II, HCl + Einger's solution ; III, in NaOH ; IV, in NaOH + Ringer ; 

 V, in Na 2 HP0 3 + KH 2 P0 3 ; VI, in Na 2 HB0 3 + HCl or +NaOH ; VII, in NA + HA. 



the buffer used, the curve for the acetate mixture lying well above the curve 

 for the phosphates. This observation is in line with Bechhold's statement 

 that the phosphates have a greater power of reducing the swelling of 

 gelatine than the acetates. It should be noted here that the molecular 

 concentration of the solutions is as follows : — Phosphates, M/15 ; borates, 

 M/10; acetates, M/5. The concentration, however, does not materially 

 affect the final equilibrium. 



The region of least swelling for the excised stern o-cutaneous is in all 

 solutions from P H = 5 to P H == 7. In the phosphate mixture the weight 

 of the muscle falls to 87"5 per cent, of its initial weight. This region is 

 one in which the muscles are coagulated. They are quite opaque in 

 appearance, and the fibres are contracted. The iso-electric point for the 

 muscle colloids undoubtedly falls within these two values, and it is 

 interesting to note in this connection that the iso-electric points of serum 

 globulin and albumen are also in this neighbourhood. It can be seen from 

 the phosphate curve in fig. 2 that at P H = 5, the muscles are coagulated and 

 shrunken. At P H = 4 on the acetate curve, the hydrogen ion concentra- 

 tion is sufficiently great to cause the muscle to swell to 270 per cent, of its 

 original weight. The rise of the curve on the alkaline side is much more 



