Influence of Antipyretics on Hearing. 23 



acuity was afterwards tested at definite intervals of time. Only 

 therapeutic doses of the drugs were administered. The following 

 substances were studied: acetanilid, acetphenetidin, antipyrin, 

 pyramidon, lactophenin, salol, aspirin, quinin, sodium salicylate, 

 and "melubrin." After studying the effects of individual drugs, 

 certain combinations were administered. The following were 

 among the combinations studied: acetanilid plus sodium bicar- 

 bonate, acetphenetidin plus salol, acetanilid plus salol, acetanilid 

 plus acetphenetidin, antipyrin plus aspirin, and antipyrin plus 

 salol. 



The results obtained were both interesting and unexpected. 

 It was found that some drugs decrease the acuity of hearing while 

 others increase it. Furthermore, it was found that certain com- 

 binations of antipyretics produce synergistic effects not explain- 

 able by the simple arithmetical sum of the effects produced by the 

 components individually. Among the agents found to decrease 

 the acuity of hearing were acetanilid, salol, and aspirin. Among 

 those found to increase the hearing were antipyrin, pyramidon, 

 and small doses of quinin. Among the most remarkable com- 

 binations studied were those of acetanilid plus sodium bicarbonate 

 and acetanilid plus salol. It was established that whereas aceta- 

 nilid given alone decreases the acuity of hearing, and ordinary 

 doses of sodium bicarbonate given alone produce no change; 

 a combination of the two produced a definite improvement in the 

 acuity of auditory perception. Again, whereas acetanilid and 

 salol when administered separately, each by itself tends to im- 

 pair the hearing, a combination of the two actually increases the 

 acuity of perception. The peculiar synergism of acetanilid with 

 sodium bicarbonate recalls the experiments of Hale who called 

 attention to the fact that such a combination is less toxic for 

 animals than the same dose of acetanilid given alone. Experi- 

 ments are in progress with a view to attempt an explanation of 

 this peculiar synergism, and complete data of the research will 

 be published in due time. 



