But there have been numerous investigators of spiritualism who cannot be placed in any such category, many of them men of high standing in the scientific world, whose word is still taken as positive evidence in support of very surprising scientific statements, since they are known to examine and test phenomena with the closest and most accurate scrutiny. This class of observers is particularly abundant in the London scientific world, and includes in its list such noted names as Alfred Russel Wallace, the celebrated naturalist, Dr. William Crooks, whose discoveries in chemistry and physics have been of a remarkable character, and Dr. Huggins, the equally celebrated astronomer. In America the most noted scientific observer was the late Dr. Hare, of Philadelphia, a chemist of world-wide fame. Of those who, if not professed scientists, have been otherwise of high standing, Professor Wallace names, in a recent communication to the "Times," Dr. Robert Chambers, Dr. Elliotson, and Professor William Gregory, of Edinburgh, Dr. Gully, a scientific physician of Malvern, and Judge Edmonds, one of the best known American lawyers. Names of similar reputation in the scientific and professional world might be adduced from Germany and France, prominent among them the late Professor Zöllner, of Leipsic, a well-known astronomer; but the above-given will suffice as evidence that the investigation of spiritualism has not been confined to the unknown, unlearned, and credulous, but has been pursued by men of the very highest standing for probity, learning, sound judgment, and critical discrimination.