AUTHOR S ABSTRACT OF THIS PAPES ISSUED 

 BT THE BIBLIOGRAPHIC SERVICE, SEPTEMBER 29 



THE TOXICITY OF ACIDS TO CILIATE INFUSORIA 



M. E. COLLETT 



University oi Pennsylvania 



SIX GRAPHS 



INTRODUCTION 



Many workers have studied the toxic effect of acids and have 

 tried to arrive at an explanation of their mode of action. Very 

 few of the experiments, however, are quite satisfactory. One 

 difficulty lies in the choice of material: for example, in studies of 

 the effect upon dogs of the feeding (Walter, '77) or intravenous 

 injections of acids (Szili, '09) or the effect upon fish or tadpoles 

 of adding acids to the external medium (Loeb and Wasteneys, 

 '12; Roaf-Whitley, '04; Unger, '16; Winogradoff, '11), the 

 material is too complex for a ready analysis of results. Some of 

 the best work of the sort is that of Winogradoff ('11), who 

 watched the process of injury to heart, corpuscles, muscle, etc., 

 in small transparent tadpoles. More satisfactory material has 

 been found in tissue or isolated cells, such as rootlets, muscle,, 

 ciliated cells, and erythrocytes (Kahlenberg-True, '96; Loeb,, 

 '98; Harvey, '14; Landsteiner and Prasek, '13) where conditions 

 are much less complex. Aside from obvious crudities, such 

 as not guarding against evaporation or not indicating time accu- 

 rately, the experiments have most often been unsatisfactory be- 

 cause of lack of data for more than one concentration of the 

 acids used or because of faulty temperature control. The usual 

 method has been to determine upon some one tissue the toxic 

 order of a series of acids, all at the same concentration (or at the 

 concentration necessary to kill in a fixed time) and then to try 

 to explain their relative toxicity by correlating the results of 

 this one experiment with the physical properties of the acids. 



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