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 portraits without overcoming by an effort the aversion
they suggest.

I am sure that the method of composite portraiture opens a fertile
field of research to ethnologists, but I find it very difficult to
do much single-handed, on account of the difficulty of obtaining the
necessary materials. As a rule, the individuals must be specially
photographed. The portraits made by artists are taken in every
conceivable aspect and variety of light and shade, but for the