304 



THE POPULAR SCIENCE MONTHLY.— SUPPLEMENT. 



Why, also, may I ask, has Dr. Carpenter, 

 ■when speaking of the radiometer, attributed to 

 me the words " new force " and " new mode of 

 force ? " They are not my words. From which 

 of my papers did he quote them ? 



The time for a mere popular preliminary 

 sketch of the radiometer is gone by ; that for its 

 thorough and exhaustive appreciation has not 

 yet come. Dr. Carpenter gives neither, but de- 

 votes the remaining part of his paper to exhibit- 

 ing as a solitary " lesson " the contrast assumed 

 to exist between Mr. Crookes, the physicist, in- 

 vestigating the phenomena of the radiometer, and 

 Mr. Crookes the " spiritualist," examining the 

 manifestations of " psychic force." To use his 

 own language, he brings " into contrast with the 

 admirable series of scientific investigations which 

 led up to that invention, his " (Mr. Crookes's) 

 " thoroughly unscientific course in relation to an- 

 other doctrine of which he has put himself for- 

 ward as the champion." 



In order to prove what he terms the " dual- 

 ity " of my mental constitution, Dr. Carpenter 

 contrasts my researches on the radiometer with 

 some experiments I made six years ago, when I 

 attempted to solve the mystery of the phenomena 

 called spiritual, and he describes the apparatus I 

 devised to test the alteration of the weight of 

 suspended bodies in Mr. Home's presence, by 

 mere contact, and without pressure. In a lecture 

 delivered at Chelsea on the 19th of January, 

 1872, Dr. Carpenter referred to this experiment ; 

 and whether his description was accurate will be 

 seen by an extract from a letter by Mr. A. R. 

 Wallace, dated February 15, 1872 : 



" In the report of Dr. Carpenter's lecture at 

 Chelsea there occurs a passage so extraordinary and 

 so entirely misleading that I must beg you, in the 

 interests of truth, to allow me to make a few remarks 

 upon it. Dr. Carpenter is stated to have said that 

 lie would grapple with Mr. Crookes's ' Psychic 

 Force ; ' and, in attempting to do so, exhibited an 

 experiment tending to show (and which his audi- 

 ence must have believed really did show) that Mr. 

 Crookes was ignorant of the merest rudiments of 

 mechanics, and was deluded by an experiment, 

 the fallacy of which an intelligent schoolboy could 

 have pointed out. Dr. Carpenter, it is said, ex- 

 hibited a glass of water poised against an equal 

 weight upon a balance, and showed that by dip- 

 ping a finger in the water — that is, by pressing 

 with a force exactly equal to the weight of the 

 water displaced by the immersed finger — you in- 

 creased the weight on that side of the balance. 

 Now, unless the audience were intended to believe 

 that Mr. Crookes was ignorant of this childishly 

 simple fact, and, further, that it completely ac- 



counted for the result of his experiment, for what 

 purpose was this experiment shown ? Yet if this 

 is what it was intended to prove, then it becomes 

 absolutely certain that Dr. Carpenter could never 

 have read Mr. Crookes's account of his experiments 

 given in October last in the Quarterly Journal, of 

 Science (for he would certainly not wilfully misrep- 

 resent the experiment), and was, therefore in com- 

 plete ignorance of what he was attempting to dis- 

 prove. For, will it be believed, Mr. Crookes ex- 

 pressly states that, ' dipping the hand to the/ idlest 

 extent into the water does not produce the least ap- 

 preciable action on the balance^ the reason of which 

 is sufficiently clear, for his woodcut shows, and his 

 description tells us, that the vessel of water was 

 not placed on the scale of a balance at all, but on a 

 board exactly over its fulcrum or point of support 

 at one end, while the distant end was suspended 

 from a balance. Yet this balance showed a force 

 of more than one pound exerted on it when Mr. 

 Elome merely dipped the tips of the fingers of one 

 hand in the water ! " 



I have no wish in this article to discuss Mr. 

 Home's psychic powers. I simply wish to ask, has 

 Dr. Carpenter described my test arrangements cor- 

 rectly, and were these arrangements scientifically 

 devised and employed, or were they, as Dr. Car- 

 penter maintains, absurd, and even childish ? 

 Dr. Carpenter says, in the Nineteenth Century : 



" Nothing would have been easier than for 

 Mr. Crookes, on the one hand, to carefully 

 watch Mr. Home, to precisely imitate his whole 

 procedure, and to do his best to depress the 

 board to the same degree by his own muscular 

 effort ; and, on the other hand, to devise an ' in- 

 dicator ' for downward pressure, by which it could 

 be at once determined whether Mr. Home could 

 depress the lever-board without such muscular 

 effort. . . . The fact was simply that the lever- 

 board went down when Mr. Home's hands were 

 laid upon it ; and the testimony of Mr. Crookes 

 and his friends was quite sufficient to justify 

 others in accepting it as such. On the other hand, 

 Mr. Crookes's assertion that the lever-board went 

 down in obedience to some other force than that 

 of Mr. Home's muscular pressure was not a fact, 

 but an inference drawn by Mr. Crookes ; and 

 this inference he had no scientific right to draw 

 until he had assured himself by every conceivable 

 test that Mr. Home did not and could not so de- 

 press it." 



Dr. Carpenter also says that I have never 

 published any proof obtained from these test- 

 experiments, although explicitly challenged to do 

 so in the Quarterly Review, October, 1871. 



Dr. Carpenter must surely know that the ex- 

 periment to which he takes exception was merely 

 the first of a series. Had he described the later 



