12 galton.org
12
Inquiries into Human Faculty
two will be observed to have an intermediate expression. The test and
measure of statistical truth lies in the degree of accordance between
results obtained from different batches of instances of the same generic
class. It will be gathered from these instances that composite portraiture
may attain statistical constancy, within limits not easily distinguished by
the eye, after some 30 haphazard portraits of the same class have been
combined. This at least has been my experience thus far.
The two faces illustrative of the same type of tubercular disease are
very striking; the uppermost is photographically interesting as a case of
predominance of one peculiarity, happily of no harm to the effect of the
ideal wan face. It is that one of the patients had a sharply-checked black
and white scarf, whose pattern has asserted itself unduly in the composite.
In such cases I ought to throw the too clearly defined picture a little out of
focus. The way in which the varying brightness of different pictures is
reduced to a uniform standard of illumination is described in the
Appendix.
It must be clearly understood that these portraits do not profess to give
the whole story of the physiognomy of phthisis. I have not room to give
illustrations of other types—namely, that with coarse and blunted features,
or the strumous one, nor any of the intermediates. These have been
discussed chiefly by Dr. Mahomed in the memoir alluded to above.
In the large experience I have had of sorting photographs, literally by
the thousand, while making experiments with composites, I have been
struck by certain general impressions. The consumptive patients consisted
of many hundred cases, including a considerable proportion of very
ignoble specimens of humanity. Some were scrofulous and misshapen, or
suffered from various loathsome forms of inherited disease; most were ill
nourished. Nevertheless, in studying
their portraits the pathetic interest
prevailed, and I returned day after day to my tedious work of
classification, with a liking for my materials. It was quite otherwise with
the criminals. I did not adequately appreciate the degradation of their
expressions for some time; at last the sense of it took firm hold of me, and
I cannot now handle the
