August 5, 1898.] 



SCIENCE. 



16c 



der Professor Newbold does not see that the 

 definition given in the first chapter is only pro- 

 visional to start the work with, that the nature 

 of suggestion and suggestibility is worked out 

 in the course of the first part, and that the final 

 definition is not arrived at before the end of the 

 eleventh chapter. 



A few words more before I conclude. Profes- 

 sor Newbold finds my physiological theory 

 rather incorrect when confronted with Apathy's 

 investigations. I do not find that my theory is 

 to any extent shaken by Apathy's ' anasto- 

 mosis.' Apathy's work may hold good for the 

 nervous system of the lower invertebrates, but 

 not of the cerebro-spinal nervous system and 

 especially of the association areas. Apathy 

 himself admits it. I am happy to say that the 

 eminent pathologist. Professor Ira Van Giesen, 

 accepts the same physiological theory, and in a 

 special work will take up this point about 

 Apathy and will furnish experimental data 

 demonstrating the truth of the position taken 

 by me in the book ' The Psychology of Sugges- 

 tion.' 



Professor Newbold' s criticism is fair and can- 

 did, and one cannot help contrasting it with the 

 virulent, almost personal, onslaught of those 

 academic psychophysicists, especially of the 

 Wundtian fold, who lack and neglect all knowl- 

 edge of mental pathology and who attack bit- 

 terly any one who has the courage to proclaim 

 openly the poor and sterile state, the trivial 

 nature of the scholastic laboratory science of 

 normal 'student psychology. ' Boris Sidis. 

 Pathological Institute of the 



New York State Hospitals, New York. 



celluloid films. 

 To THE Editor of Science : My own ex- 

 periments and sad experiences in the use of 

 celluloid ' cut films ' instead of glass plates for 

 photographic purposes on long expeditions 

 prompt me to write a warning to those who 

 will read the note quoted in Science, July 22, 

 1898, page 106. If the advice given by Mr. 

 Stillman were followed by scientists without 

 further test I greatly fear that their return 

 from a six months' expedition with numerous 

 undeveloped ' films ' safely stowed away for 

 development at leisure would be made less en- 

 joyable after a few hours in the dark room. 



Two years ago I made trial of some fresh films 

 and thought them so superior to glass because 

 of their lightness that I adopted them for use 

 on a visit by bicycle to the astronomical 

 observatories of Europe. I could not find ten 

 dozen in stock in New York without taking 

 some that were three months old. I was in 

 Europe only three months, and during that time 

 carried those films and a camera with other 

 baggage on my bicycle for two thousand miles, 

 on hot days buoyed through the ' slough of 

 despond ' by the expectation of having at least 

 one hundred fine photographs of observatories 

 and scenery. The camera was a familiar one, 

 and I had had long experience in photography 

 in America and in South and Central Africa 

 with glass plates which had always proved suc- 

 cessful. But, alas ! when I returned to the 

 States and at once proceeded to develop the 

 films I could find only the faintest traces of 

 the scenes which ought to have been there. 

 There was every indication that the acids in the 

 celluloid had destroyed the sensitiveness of the 

 emulsion either before or after exposure. Since 

 then experiments on ' films ' of various ages and 

 the questioning of professional photographers 

 who have developed many thousands of these 

 ' films ' have confirmed my belief that as a rule 

 they may be regarded as practically worthless 

 after they had been made a year, and are very 

 unreliable after six months. I mean by ' unre- 

 liable ' that it is impossible to predict by the 

 action of one plate what the time of exposure on 

 another plate of the same emulsion ought to be. 

 Hence I conclude that one should be very 

 cautious in adopting the suggestions of Mr. W. 

 J. Stillman, from whom you quote, if the expe- 

 dition is to last more than six months from the 

 time when the plates were made ; and in every 

 case I should prefer to get fresh films every 

 month and develop them as they are exposed. 



Herman S. Davis. 

 Columbia University, July 22, 1898. 



SCIENTIFIC LITERATURE. 

 Au Pays des ba-Sotsi. By Alfred Bertrand. 



Paris, France, Hachette et Cie. 4to. Pp. 333 



and 10. 104 illustrations. 



This volume, prepared in the handsome style 

 of the famous French publishing house from 



