"Le petit, animal, voulant teter, et trouvant pas de mamelles, a donne de violent coups de te^te dans le re'gion mammaire...."[2] [1] In a reference to de Sinety's vivisections at page 171, in the present volume, there is a slight mistake. Although de Sinety, as shown above, had practised the ablation of the mammary glands during lactation, it would seem that mutilation rather than complete ablation preceded his experiments on the innervation of the mammary nerve. The sentence should read "cut into the breasts," and not "removed the breasts." He tells us that he made a considerable number of experiments of the kind upon female guinea-pigs. In one of them, for example, he laid bare the nerve and isolated it with a thread,--"le nerf mammaire d'un co^te est mis a` nu, et isole," and that when the electric current was used, extreme pain,--"un douleur tre`s vivre" was excited, notwithstanding which the excitation was continued for ten minutes. (Gazette Me'd. de Paris, for 1879, p. 593). [2] Comptes Rendus de la Soc. de Biologie, Paris, 1883, p. 778. There is no need of completing the description. It was an experiment absolutely useless and without justification. We may confess that we read of such useless cruelties of experiment only with infinite disgust. No matter how careful a writer may be, it is very rare that he escapes, from unfriendly readers, the imputation of inaccuracy. Against writers of history--men like Froude, Macaulay, or Carlyle--the same charge has been made. But a critic whose microscopic eye discerns inaccuracy in others should be very careful to make no similar errors himself. The mistake upon which he has dwelt, was due to reliance upon the translation of another man. It may be of interest to point out that in his own writings Dr. Keen has made a precisely similar mistake; and that although it was pointed out and its untruth confessed many years ago, yet the false imputation appears again in the pages of his book, without correction or intimation of its utter untruth, on the page where it firs tis given to the reader of to-day. In a pamphlet published during the closing years of the last century by the American Humane Association, there appeared a strong condemnation of experiments made by a Dr. Sanarelli, apparently upon hospital patients, temporarily under his care. In an Italian periodical, the young scientist described his researches with remarkable frankness. He tells of the various symptoms of yellow fever, which by his serum he had caused his victims to suffer--the congestions, the haemorrhage, the delirium, the fatty degeneration, the collapse; and all these, he adds, "I have seen unrolled before my eyes, THANKS TO THE POTENT INFLUENCE OF THE YELLOW-FEVER POISON MADE IN MY LABORATORY."