162 



MacDOUGAL and SPOEHR— components AND 



exemplified in the swellings in solutions of various bases and deriva- 

 tives of glycocoll. It became apparent in the earlier stages of our 

 work that the effects of the alkaline hydroxides were by no means 

 equivalent, and a series of preparations were run for the purpose of 

 securing comparisons of the action of potassium, rubidium, sodium, 

 lithium, barium, strontium and calcium. The values obtained are 

 given in Table VII. 



TABLE VII. 



Swelling of Agar in Strong Alkaline Hydroxides. 

 Sections 0.14 mm. Thick at 17° C. 



0.01 N. O.OOI N. 



KOH 1,535 3,430 



RbOH 1,635 3oOO 



NaOH 1,645 3,430 



LiOH 1,820 3,430 



Water 3,000 to 3,070 



When these absolute values are compared with that obtained in 

 water the data in Table VIII. are obtained. 



TABLE VIIL 



Swelling of Dried Agar Plates 0.14 mm. in Thickness at 17'' C. in. Solu- 

 tions OF Alkaline Hydroxides which were Renewed Every 12 Hours. 

 Total swelling of dried agar plates in water 3,035 per cent. 



It is to be seen that these alkaline hydroxides may be carried to 

 an attenuation where they may cause a swelling of agar greater than 

 in water, an effect hitherto found only with amino-compounds. The 

 stronger the base as indicated by its position in the electromotive 

 series, the more does it restrict hydration. All reverse that effect 

 and become accelerating agents at a greater dilution. Rubidium is 

 the exception in the table, and its aberrant position may be ascribed 

 to error until material is available for a repetition of the tests. 



In the hydroxides of the alkaline earths the variations are not 

 so clearly defined. Unfortunately the quantitative relations of these 



