ENVIRONMENT AND REGENERATION 



483 



Regeneration in acids 



As the previous experiments show, neutraUty is more favorable 

 for regeneration in tadpoles than basicity. Is the same true 

 for acidity? A complete series from acids almost certain to have 

 detrimental effects to bases known to be harmful was formed 



TABLE 4 

 Regeneration in NaOH. Length of tadpoles 37-40 mm. 



1 The maximum reduction in pH value occurred the first day of the experiment; 

 the minimum the fourth day, the day in which the tadpoles died. 

 Total length and readings for tenth and fourteenth days omitted. 



by using 25, 20, 15, 10, and 5 cc. 0.01 mol. H3PO4 and 5, 10, 12.5, 

 15, 17.5, and 20 cc. O.OIN NaOH made up to 200 cc. with 

 distilled water. A control containing 5 cc. of a 0.01 mol. neutral 

 solution of Na2HP04, and KH2PO4 was added to the usual 

 distilled-water controls. The solutions were changed daily. It 

 was hoped by this series to locate approximately the optimum 

 hydrogen ion concentration for regeneration. 



