72 CICATRIZATION OF WOUNDS 



whole and quantitatively as I had been taught to do for a 

 physical phenomenon. Dr. Carrel had foreseen that a brain 

 trained in such methods was better adapted to attack this 

 problem than one inhibited by a mass of knowledge and by 

 habits of thought. 



The problem was then momentarily reduced to finding a 

 way of obtaining a constant value for this formula by intro- 

 ducing a 'new measurable element, varying in the same 

 manner as the differences observed between the experimental 

 values and those calculated from the formula. 



First of all, of what order of magnitude were the dis- 

 crepancies, and what was the law of their variation? 



Let us go back to wound no. 221. We have seen that the 

 cicatrized area was 5-5 square centimetres between the first 

 and fourth day; this gave the following values for formula (2) 

 (5'=i6-2; S'=io-7) 



= — — — = 0-085 (in round figures). 



Sxt 16-2x4 



For the second period of four days, we find: 



5"= 10-7; S" (surface after eight days)=6-5 therefore 

 S'-S"=4-2 and 



= — -^ — = 0-098. 



^ xr 10-7x4 



The difference is slight, but nevertheless exists. The same 

 calculation made for the fourth period gives 0-119, the fifth 

 period gives 0-136 and the sixth 0-175 (^^e area of the wound 

 is now equal to one square centimetre). It was obvious that 

 I was far from having a. constant to deal with. Fig. 14 clearly 

 shows the extent of my error in the shaded area. This error, 

 as can be seen, was considerable and affected the last figure 

 calculated by 100 per cent (0-67 instead of 033). On other 

 wounds it was still more important. 



All the values of 5" which could be derived from the formula 

 were too high. Hence, it was clear that it was thfe denominator 

 which must be augmented. But it could not be increased by 

 a constant coefficient, for the values of the entire formula 



