By advanced instruction and post-graduate classes the student is led on to take active part under licensed authority in this fascinating, but morally dangerous, method of study. Moreover, the large body of subordinates who are necessary to take charge of and prepare the animals, are trained in indifference to suffering, without any excuse of intellectual gain, and the same injurious influence extends in ever-widening circles--to the traders who invent and sell instruments of torture, and to those who supply the living material. Now, the natural instinct to be cherished in human beings is protection and kindliness to infancy and all helpless creatures, not indifference to suffering or wilful infliction of it. As human conscience is a thing of growth or degradation, the natural shrinking from needless pain can soon be hardened into callousness. Conversing with medical students in relation to the effect made upon them by witnessing vivisections even under chloroform, I have found that their experience is always the same--viz., first, the shock of repulsion, then tolerance, and then, if often repeated, indifference. The moral deterioration necessarily induced in those to whom suffering becomes a frequent spectacle is noted by the _Englishman in Paris_, from personal experience. After speaking of the inhumanity produced by the daily sight of blood in the originally honest bourgeois, who became the ‘Conventionnels’ of the French Revolution in 1793, he writes as follows: ‘I have witnessed three executions. After Pommeraye’s execution I was ill for a week; after Troppmann’s the effect soon wore off in three days; after Campa’s I ceased to think about it in twenty-four hours. Then I made a vow that no power on earth should draw me to the Place de la Roquette again. But men generally regard their growing imperviousness as a sign of mental force, and pride themselves upon it.’ In Marie Bashkertseff’s _Journal_ is a striking passage which describes the effect of a Spanish bull-fight. She says: ‘I was able to maintain a tranquil air in full view of the butchery, carried on with the utmost refinement of cruelty. One leaves the scene slightly intoxicated with blood, and feeling desirous to thrust a lance into the neck of every person one meets. I stuck my knife into the melon I was cutting at table as if it were a banderilla I were planting in the hide of a bull, and the pulp seemed like the palpitating flesh of the wounded animal. The sight is one that makes the knees tremble and the head throb. It is a lesson in murder.’