82 



CICATRIZATION OF WOUNDS 



advantage besides that of simplicity and economy of time, 

 namely, that of precision. For, if two measurements are made 

 at four days' interval, it may happen that during this time 

 shght incidents escaping our observation occur, which can 

 momentarily retard or accelerate cicatrization. The index 

 calculated from the amount cicatrized during those four days 

 will therefore be inaccurate, and the whole curve equally so. 

 As we have seen above, a wound comes back to its normal 

 rate when the local causes of perturbation are eliminated. The 

 index furnished by the chart is independent of this cause of 

 error. 



I spoke of retardation, which can be due to a traumatism or 

 to infection, and also of acceleration. This latter phenomenon 

 takes place, for example, when a wound rapidly epithelizes 

 small crannies like those represented in Fig. i8. The figures 

 below show the error that would have been made if the index 

 had been calculated between the 20th and 24th of May (the 

 patient was thirty-one years old). 



If the index obtained from tlie chart is used, the discrepancy 

 between the two figures on the 24th of May is wiped out on 

 the 5th of June. The theoretical index obtained from the 

 chart was 0-032, That given by calculation was 0047. The 

 error would therefore have been important, and the use of the 

 chart eliminates it completely. Finally, this method has the 

 following third serious advantage. The index obtained from 

 the chart being a mean value, corresponding to a normal 

 asceptic cicatrization on a normal individual, if, independently 



