The unpleasant accompaniment of all criticism is misunderstanding. A protest, a remonstrance of any kind can gain a hearing only after it has been repeated again and again, and even then it is quite as liable as otherwise to be wholly misconstrued. It has been with very great regret that for many years, I have found myself in disagreement with so large a number of medical writers, who have left behind them the conservatism of earlier opinions in the English-speaking world, to follow the newer lights of Continental freedom and irresponsibility. The regret is the more poignant, because, speaking from the vantage of seventy years, I believe that the highest realization of human hopes for the welfare of our race, must come through medical science. It is, however, to preventive medicine that the world must learn to look, not to the conquest of disease by new drugs or new serums. There are ailments, which every year in England and America are responsible for thousands of preventable deaths. That fifty years hence, these scourges of humanity will be curable by the administration of any remedy, to be hereafter discovered by experimentation on animals,--in the Rockefeller Institute, for instance,--I have not the slightest faith. It is not through the torment of living creatures, not through the limitless sacrifice of laboratory victims, not through the utilization of babes as "material" for research, that medical science will yet achieve for humanity its greatest boon,--the prevention of disease. I venture with confidence, to make that forecast of the future, leaving recognition of its truth to those who shall come after us, when all now living shall have passed away. APPENDIXES SECOND EDITION -------- APPENDIX I "ANIMAL EXPERIMENTATION AND MEDICAL PROGRESS"--A REVIEW By a curious coincidence, two books relating to vivisection were published in America at almost the same time. One, under the above title, was a collection of essays and contributions to various periodicals from the pen of Dr. William W. Keen, which have appeared during the past thirty years. The other was the first edition of the present work.