_A. Rambacher_, as he relates in a pamphlet, sent the scientific treatise on Lourdes by Dr. _Boissarie_ to Prof. _Haeckel_, with the request to read it, in order to gain a better notion of the existence of a supernatural world. After some urging he finally received the following reply, which speaks volumes for the attitude of the natural scientist towards facts: “With many thanks I hereby return the book by Dr. _Boissarie_ on the Great Cures of Lourdes which you sent me. The perusal of the same has convinced me anew of the tremendous power of superstition (glorified as ‘pious belief’) of naïve credulity (without critical examination), and of contagious collective suggestion, as well as of the cunning of the clergy, exploiting them for their gain.... The physicians, said to testify in behalf of the ‘miracles’ and the supernatural phenomena, are either ignorant and undiscerning quacks, or positive frauds in collusion with the priests. The most accurate description of the gigantic swindle of Lourdes I know of, is that of _Zola_ in his well-known novel.... With repeated thanks for your kindness ... _Ernst Haeckel_.” Against all the facts in evidence this dogmatic scientist was safely intrenched behind the stone wall of his presumptions. He knew in advance that everything was superstition or the fraud of cunning priests, that all physicians who certified to cures were quacks and cheats. _Zola’s_ tendentious romance considered the best historical source! Mention should be made here how this celebrated novelist dealt with facts at Lourdes. In the year 1892, the time of the great pilgrimage, _Zola_ went to Lourdes. He wanted to observe and then tell what he had seen. An historical novel it was to be; time and again he had proclaimed in the newspapers that he would tell the whole truth. At Lourdes all doors were opened to him; he had admittance anywhere; he could interview and obtain explanations at will. How he kept his promise to report the truth may be shown by a single instance: _Marie Lebranchu_ came to Lourdes on August 20, 1892, suffering from incurable consumption. She was suddenly cured, and never had a relapse. One year after her cure she returned to the miraculous Grotto. The excellent condition of her lungs was again verified. Now, what does _Zola_ make of this event? In his novel the cured girl suffers a terrible relapse upon her first return home, “a brutal return of the disease which remained victorious,” we read in _Zola’s_ book. One day, the president of the Lourdes Bureau of Investigation introduced himself to _Zola_ in Paris, and asked him “How dare you let _Marie Lebranchu_ die in your novel; you know very well that she is alive and just as well as you and I.” “What do I care,” was _Zola’s_ reply, “I think I have the