254   MEMORIES OF MY LIFE

in the ordinary sense of the word. Professor Tyndall ascribed its adaptation of form to a succession of internal crunches and re-freezings ; in other words, to successive conditions of stability.

I t became gradually clear that three facts had to be established before it would be possible to advocate the use of finger-prints for criminal or other investigations. First, it must be proved, not assumed, that the pattern of a finger-print is constant throughout life. Secondly, that the variety of patterns is really very great. Thirdly, that they admit of being so classified, or " lexiconised," that when a set of them is submitted to an expert, it would be possible for him to tell, by reference to a suitable dictionary, or its equivalent, whether a similar set had been already registered. These things I did, but they required much labour.

A Committee was appointed by the Home Office to inquire into the different systems of identification that had been adopted or proposed for use with criminals. They visited my Laboratory, and thoroughly inspected what I had to show. It was a great pleasure to work with and for such sympathetic and keen inquirers, but I regretted all the time that my methods were hardly ripe for inspection ; still, they were fairly adequate. The result was a Report strongly in favour of their adoption, of which the part that bears, on finger-prints is reprinted in my Finger Print

Directory [ 13 1 ].

I had communicated with M. Alphonse Bertillon, suggesting that he should consider the introduction of finger-prints into his own system, but the idea did not commend itself to him. Afterwards I sent