348 



BOOKS AND CURRENT LITERATURE 



5. Alkalies increase the swelling to 

 a greater extent than do acids. 



6. The amount of swelling under 

 the influence of any given electrolyte 

 depends upon its concentration, in- 

 creasing up to a known amount and 

 then decreasing with further concen- 

 tration. 



7. The addition of a salt to an acid 

 or a basic solution lowers the swelling 

 rate. 



8. The degree of the effect of salt 

 on swelling is due to the sum of the 

 effects of the salt and the ions 

 formed. 



9. When arranged in the order of 

 their power to decrease swelling in an 

 acid solution the salts used appear as 

 follows : 



anions: Cl< Br< N03< SCX< I< 

 CH3COO<S03 ; 



cations : K < Na< NH4< Mg< Ca< 

 Ba<Sr<Cu<Fe. . 



5. Inorganic bases do not appre- 

 ciably increase growth rate. 



6. The amount of acceleration of 

 growth depends upon the concentra- 

 tion of the acid up to a certain point, 

 after which it decreases with further 

 concentration, and finally with still 

 higher concentrations death results. 



7. The addition of a salt to an 

 acid solution lowers the growth rate 

 which appeared in the presence of the 

 acid solution. (One or two exceptions 

 appear.) 



8. The rate of growth depends upon 

 the quantity of acid present as well as 

 upon the concentration of the salt. 



9. When arranged in the order of 

 their jjower to decrease growth rate 

 when added to an acid solution, the 

 salts appear as follows: 



anions: Cl< S03< Br< N03< C. O, H3 

 CNS<S: 



cations: K< Na< Li< NH4< Ca< Ba< 

 Sr<Cu. 



The second paper is concerned with the one case of lack of agreement 

 between the action of the hydration of colloids and the growi:h rate, 

 namely, the behavior of bases. Organic bases of various strengths were 

 tested with the result that they show a slight decrease in growth rate. 



This failure of Helianthus to show an increased gro^vth rate in solutions 

 of bases is held to be due to the formation of neutral protoplasmic mole- 

 cules. This conclusion is based on the agreement of growth rates with 

 the results of Handowsky's work on egg albumen. Handowskj^ proved 

 the existence of neutral molecules formed in albumen in the presence 

 of certain organic compounds and Borowikow finds that, in general, 

 those compounds which favor the ionization of albumen, increase the 

 hydration of plasma colloids, and through this the groAvth rate of the 

 plant. Organic bases increase the number of neutral particles in albu- 

 men and thus decrease the hydration capacity, while acids increase the 

 number of positive ions and the hj'^dration capacity. In this way the 

 decrease in growth shown in the presence of bases in held not to be a 

 real exception to the analogy between the hj^dration capacity of col- 

 loids and the growth rate of Helianthus. 



