May 8, 1896.] 



SCIENCE. 



689 



having him look at a series of words for 

 about 5 seconds, and then repeat as many 

 as he could in correct order. He succeeded 

 in repeating correctly 5 out of a series of 6 

 words, and 6 out of 9 words. For a similar 

 series of numbers his memory was much 

 better. He could repeat 7 numerals cor- 

 rectly, and in attempting to repeat a set of 

 10 made but 2 errors. This is better than 

 the average, but not remarkably so. It 

 should be added that several very striking 

 performances are given by Mr. Kellar in 

 which memory forms a considerable part. 

 It is, however, a very special form of 

 memory, involving the formation of ac- 

 curate associations and classifications rather 

 than an extended series of impressions. 



If we now select those tests in which the 

 records of Mr. Hermann and Mr. Kellar 

 differ markedly from the normal we find 

 as follows: In the quickness of response 

 to a touch and a visual stimulus both the 

 special subjects, and Mr. Kellar as well in 

 response to an auditory stimulus, excel to 

 a considerable extent the average individ- 

 ual. But this quickness of reaction does 

 not appear in the more complicated reac- 

 tions; and in the most complicated reaction 

 they both fall considerably below the nor- 

 mal. In the quickness of movement we 

 find decided indications of an unusual 

 quickness for both Mr. Hermann and Mr. 

 Kellar. In the scope and accuracy of visual 

 perception we find in part a good record, 

 but on the whole no very decided excel- 

 lence appears. In tests involving mainly 

 tactual perception and muscular perception, 

 the indication is rather that they are below 

 than above the normal. I might also add 

 that I have repeated a few of these tests 

 upon a local sleight-of-hand performer, and 

 find for him a good record and particularly^ 

 a great quickness of movement. This is 

 perhaps to be explained by his facility in 

 musical execution as a pianist and organist 

 as well as in sleight-of-hand performance. 



The positive results of the investigation 

 are thus small, but as far as they go they 

 ai'C consistent with the forms of dexterity 

 that are utilized in sleight-of-hand perfor- 

 mances. They also indicate that it may 

 ■(veil be that special skill " in one very 

 specialized form of training may be only 

 slightly influential upon other forms of 

 capacity. So little is known of the correla- 

 tion of powers of this kind, and small series 

 of tests are so apt to be affected by accidental 

 errors, that any suggestions which the data 

 seem to warrant must be put forward with 

 great caution. The individual is intei-esting, 

 but the methods of I'esearch are, and must 

 be, particularly adapted to statistical 

 groups.* 



Joseph Jasteow. 



University of Wisconsin. 



THE INFLUENCE OF CARBON DIOXIDE 



ON THE PB0T0PLA83I OF LIVING 



PLANT CELLS. 



The history of investigation of the rela- 

 tions of plants to the component gases of 

 atmospheric air and with special reference 

 to CO2 may be said to begin with the re- 

 searches of Priestley and Ingenhousz 

 (1779) . Among the results obtained by the 

 latter was the fact that plants die in ' air ' 

 fatal to animals, and that such air contained 

 large portions of CO,. De Saussure next 

 made his famous tests of the eflects of the 

 atmospheres containing various proportions 

 of GO., upon growth (1804), and John found 

 that peas would not germinate in an atmos- 

 phere of this gas, and since the seeds were 

 killed by the alcoholic fermentation accom- 



* I feel that it is necessary to add that Mr. Hermann 

 perhaps did not do himself justice in some of the tests. 

 He "was always quick, confident and decided in his 

 judgments, often performing a test in half the time 

 tat en by the average person. He was much interested 

 in the tests, hut seemed confident of his ability to do 

 what was required, with little effort. It may well be 

 that with a little more deliberation, and an oppor- 

 unity of even a brief familiarity with the tests, better 

 results could have been secured. 



