Clearly no definite conclusion could be based on such figures as the above. They at most contained a hint for more extended trials, but a hint, fortunately, which can be easily followed up. We are often asked by acquaintances what they can do to aid the progress of psychical research. These experiments suggest a most convenient answer; for they can be repeated, and a valuable contribution made to the great aggregate, by any two persons who have a pack of cards and a little perseverance.1

1 It should be remarked, however, that the introduction of any principle of selection, after one experiment, is always objectionable. For some more or less plausible reason could probably always be found for setting aside the less favourable results.

Up to the time that I write, we have received, in all, the results of 17 batches of trials in the guessing of suits. In 11 of the batches one person acted as agent and another as percipient throughout: the other 6 batches are the collective results of trials made by as many groups of friends. The total number of trials was 17,653, and the total number of successes was 4,760; which exceeds by 347 the number which was the most probable if chance alone acted. The probability afforded by this result for the action of a cause other than chance is '999,999,999,1 -or practical certainty.2 I need hardly say that there has been here no selection of results; all who undertook the trials were specially requested to send in their report, whatever the degree of success or un-success; and we have no reason to suppose that this direction has been ignored. It is thus an additional point of interest that in only one of the batches did the result fall below the number which was the most probable one for mere chance to give.

And if we take only those batches, 10 in number, in which a couple of experimenters made as many as 1,000 trials and over, the probability of a cause other than chance which the group of results yields is estimated by one method to be *999,999,999,96, and by another to be '999,999,999,999,2.

To this record must be added another, not less striking, of experiments which (though part of the same effort to obtain large collective results) differed in form from the above, and could not, therefore, figure in the aggregate. Thus, in a set of 976 trials, carried out by Miss B. Lindsay (late of Girton College), and a group of friends, where the choice was between 6 uncoloured forms - 9 specimens of each being combined in a pack from which the agent drew at random - the total of right guesses was 198, the odds against obtaining that degree of success by chance being about 500 to 1. In another case, the choice lay between 4 things, but these were not suits, but simple colours - red, blue, green, and yellow. The percipient throughout was Mr. A. J. Shilton, of 40, Paradise Street, Birmingham; the agent (except in one small group, when Professor Poynting, of Mason College, acted) was Mr. G. T. Cashmore, of Albert Road, Handsworth. Out of 505 trials, 261 were successes. The probability here afforded of a cause other than chance is considerably more than a trillion trillions to 1. And still more remarkable is the result obtained by the Misses Wingfield, of The Redings, Totteridge, in some trials where the object to be guessed was a number of two digits - i.e., one of the 90 numbers included in the series from 10 to 99 - chosen at random by the agent.

Out of 2,624 trials, where the most probable number of successes was 29, the actual number obtained was no less than 275 - to say nothing of 78 other cases in which the right digits were guessed in the reverse order. In the last 506 trials the agent (who sat some 6 feet behind the percipient) drew the numbers at random out of a bowl; the odds against the accidental occurrence of the degree of success - 21 right guesses - obtained in this batch are over 2,000,000 to 1. The argument for thought-transference afforded by the total of 275 cannot be expressed here in figures, as it requires 167 nines - that is, the probability is far more than the ninth power of a trillion to 1.

1 The rules to observe are these: (1) The number of trials contemplated (1,000, 2,000, or whatever it may be) should be specified beforehand. (2) Not more than 50 trials should be made on any one occasion. (3) The agent should draw the card at random, and cut the pack between each draw. (4) The success or failure of each guess should be silently recorded, and the percipient should be kept in ignorance of the results until the whole series is completed. [The results should be sent to the Secretary of the Society for Psychical Research, 20 Hanover Square, W].

² For these calculations we have again to thank Mr. F. Y. Edgeworth. For an explanation of the methods employed, see his article in vol. iii. of the Proceedings of the S.P.R., already referred to, and also his paper on "Methods of Statistics" (sub fin.) in the Journal of the Statistical Society for 1885.

Card-experiments of the above type offer special conveniences for the very extended trials which we wish to see carried out: they are easily made and rapidly recorded. At the same time it must not be assumed that the limitation of the field of choice to a very small number of known objects is a favourable condition; it is probably the reverse. For from the descriptions which intelligent percipients have given it would seem that the best condition is a sort of inward blankness, on which the image of the object, sometimes suddenly but often only gradually, takes shape. And this inward blankness is hard to ensure when the objects for choice are both few and known. For their images arc then apt to importune the mind, and to lead to guessing; the little procession of them marches so readily across the mental stage that it is difficult to drive it off, and wait for a single image to present itself independently. Moreover idiosyncrasies on the guessers' part have the opportunity of obtruding themselves - as an inclination, or a disinclination, to repeat the same guess several times in succession. These objections of course reach their maximum if the field of choice be narrowed down to two things - as where not the suit but the colour of the cards is to be guessed.