September 4, 1885.] 



SCIENCE. 



199 



of his results, we are sorrj^ to say, add nothing 

 to our gross experience of the matter. Here, 

 as in the case of the saints, heroism seems to 

 be its own reward. But the incidental results 

 are usually the most pregnant in this depart- 

 ment ; and two of those which Dr. Ebbinghaus 

 has reached seem to us to ampl}^ justify his 

 pains. The first is, that, in forgetting such 

 things as these lists of syllables, the loss goes 

 on ver}^ much more rapidly at first than later 

 on. He measured the loss by the number of 

 seconds required to relearn the list after it had 

 been once learned. Roughly speaking, if it 

 took a thousand seconds to learn the list, and 

 five hundred to relearn it, the loss between 

 the two learnings would have been one-half. 

 Measured in this way, full half of the forgetting 

 seems to occur within the first half-hour, whilst 

 only four-fifths is forgotten at the end of a 

 month. The nature of this result might have 

 been anticipated, but hardly its numerical pro- 

 portions. 



The other important result relates to the 

 question whether ideas are recalled only by 

 those that previously came immediatel}^ before 

 them, or whether an idea can possibly recall 

 another idea, with which it was never in 

 immediate contact, without passing through 

 the intermediate mental links. The question 

 is of theoretic importance with regard to the 

 way in which the process of ' association of 

 ideas ' must be conceived ; and Dr. Ebbing- 

 haus's attempt is as successful as it is original, 

 in bringing two views, which seem at first 

 sight inaccessible to proof, to a direct practical 

 test, and giving the victory to one of them. 

 His experiments conclusively show that an 

 idea is not only ' associated ' directly with the 

 one that follows it, and with the rest through 

 that, but that it is directly associated with all 

 that are near it, though in unequal degrees. 

 He first measured the time needed to impress 

 on the memory certain lists of S3'llables, and 

 then the time needed to impress lists of the 

 same syllables with gaps between them. Thus, 

 representing the syllables by numbers, if the 

 first list was 1, 2, 3, 4 . . . 13, 14, 15, 16, the 

 second would be 1, 3, 5 ... 15, 2, 4, 6 .. . 16, 

 and so forth, with manj^ variations. 



Now, if 1 and 3 in the first list were learned 

 in that order merely b}^ 1 calling up 2, and by 

 2 calling up 3, leaving out the 2 ought to leave 

 1 and 3 with no tie in the mind ; and the 

 second list ought to take as much time in the 

 learning as if the first list had never been 

 heard of. If, on the other hand, 1 has a direct 

 influence on 3 as well as on 2, that influence 

 should be exerted even when 2 is dropped 



out ; and a person familiar with the first list 

 ought to learn the second one more rapidl}^ 

 than otherwise he could. This latter case is 

 what actually occurs ; and Dr. Ebbinghaus 

 has found that syllables originally separated 

 by as man}^ as seven intermediaries, still 

 reveal, b}" the increased rapiditj^ with which 

 they are learned in order, the strength of the 

 tie that the original learning established be- 

 tween them, over the heads, so to speak, of 

 all the rest. It may be that this particular 

 series of experiments is the entering wedge 

 of a new method of incalculable reach in 

 such questions. The future alone can show. 

 Meanwhile, when we add to Dr. Ebbinghaus's 

 ' heroism ' in the pursuit of true averages, his 

 high critical acumen, his modest tone, and his 

 polished style, it will be seen that we have 

 a new-comer in ps^'chology, from whom the 

 best may be expected. W. J. 



NOTES AND NEWS. 



The articles of scientific interest in the general 

 English and American magazines for August are 

 neither numerous nor interesting. Two topics seem to 

 have monopolized the popular scientific mind during 

 the midsummer months, — dogs and cholera. 



There are two articles on dogs worth mentioning. 

 One is a paper in Bailey'' s monthly magazine on ' The 

 descent of the foxhound,' in which the writer at- 

 tempts to show that the foxhound was produced 

 about the beginning of the eighteenth century by a 

 process of careful selection, and not, as some have 

 supposed, by crossing a swift-footed hound with some 

 dog of keener scent. In the Century appears the 

 second part of Mr. John E. Thayer's beautifully illus- 

 trated account of 'Typical dogs.' A clear and con- 

 cise account is given of the appearance, traits, etc., 

 of the water spaniels, collies, and fox-terriers. 



Six gentlemen of the medical profession have taken 

 occasion to express themselves on the cholera ques- 

 tion. 



In the Nineteenth century, Dr. Charles Connor, in 

 an article entitled * Anti-cholera inoculation,' at- 

 tempts to show statistically that Dr. Ferran's experi- 

 ments have been more successful than those of 

 Jenner were; and that by the anti-cholera vaccination 

 process the danger of dying from cholera is made 

 about six times less than it would be under normal 

 circumstances. Dr. J. Burdon Sanderson, in the 

 Contemporary review, gives his views on the causes 

 and prevention of cholera. This writer gives a brief 

 sketch of the history of cholera, shows to his own 

 satisfaction that Koch's comma bacillus has nothing 

 to do with cholera, and then goes on to say the 

 ordinary things about good drainage, careful diet, 

 etc. But it is in the North- American review that the 

 greatest number of articles, and the least amount of 

 information, is to be obtained on the subject of Asiatic 



