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Scientific Proceedings (127) 



two spots in the same room. The statement of Macht, Green- 

 berg and Isaacs that the intensity of the sound varies as the 

 square of the distance assumes a point source with no reflections 

 from surrounding objects. It is not true for any sort of an en- 

 closed space. For this reason we were interested in the factor 

 of experimental error established for the watch tick tests. It 

 is impossible from the data given to determine the variations 

 in the normal readings because the investigators did not always 

 use the same watch. They were necessarily more interested in 

 ratio diffrences. However one table is offered which indicates 

 the surprising accuracy of the method employed. 



The results on single drug effects are summarized in their 

 table 12 on page 163 and which we reproduce as given with one 

 minor correction in the printing, i.e., sodium salicylate should 

 read 74 per cent, instead of 94 per cent. 



Acetanilide 78 per cent, normal 



Aeetphenetidin 129 per cent, normal 



Pyramidon 117 per cent, normal 



Antipyrine 148 per cent, normal 



Lactophenin 139 per cent, normal 



Melubrin 150 per cent, normal 



Salol 77 per cent, normal 



Sodium salicylate 74 per cent, normal 



Acetylsalicylic acid 77 per cent, normal 



Quinine 110 per cent, normal 



Sodium bicarbonate 100 per cent, normal 



Aspirin 77 per cent, normal 



"It was found that acetanilide, sodium salicylate, acetylsali- 

 cylic acid, phenyl salicylate, and some other drugs decreased the 

 threshold of hearing." "It was found that aeetphenetidin, anti- 

 pyrine, pyramidon and some other drugs increased the thresh- 

 old of hearing." The expressions '"increased" and "decreased" 

 as applied to the threshold of hearing might in this instance be 

 interpreted in terms of acuity of hearing. The first named 

 group of drugs decreased while the last named group increased 

 the acuity of hearing. 



It is extremely important in work on minimum audibility that 

 the variable factor of attention be carefully borne in mind. 

 While no definite information is available on the variable normal 

 for the watch tick tests, the table on the effects of sodium bicar- 

 bonate is extremely interesting. In twelve tests in this table the 

 distances before and after administration are exactly the same. 



