Certain Reactions of Biocolloids and Cell-masses. 71 



The decreased swelling in swamp water and the high swelling in bog 

 water were marked and invariably shown. 



However, the biocoUoid approaches more nearly to the condition of 

 the protoplast when, in common with all living matter, it includes some 

 salts. The above mixture containing culture salts was not avail- 

 able, but some plates in which the oat protein was replaced by bean 

 protein to which had been added 0.8 per cent of culture salts were 

 swelled in a parallel series. The untreated mixture free from the 

 added salts does not show as high an imbibition capacity as that made 

 up with the oat protein. The measurements of the increase of the 

 agar-bean protein-salted sections at 15° C. were as shown herewith: 



Table 61. 



p. ct. 



Distilled water 1 , 525 



Bog water 1,525 



Swamp water 1 , 100 



Calcium nitrate, 0.008 M 825 



These measurements were taken at the end of 40 hours, while some 

 increase was still in progress, but the final relations would not have 

 been materially altered by the use of the end-points for the compari- 

 sons. The retarding action of the swamp water and the equivalence 

 of swelUng in pure water and bog water therefore runs plainly defined 

 through all of the experiments with living and dried sections of plants 

 and in tests with salted and unsalted biocolloids. Calcium nitrate in 

 the concentration used exercises a more marked effect on the salted 

 biocoUoid than on the unsalted mixture and on the plant material. 

 The calcium content of the biocoUoid is probably much higher than 

 that of the plant, so that the two sets of measurements are not strictly 

 comparable. 



The calcium solution contained about eight times as much salt as 

 the bog water and nearly three times as much as the swamp water, 

 which also includes a trace of sodium chloride. A series was therefore 

 arranged to compare the action of the two with equivalent salt solu- 

 tions. Sections of agar and bean protein impregnated with 0.8 per 

 cent of culture salts were swelled at 15° C. with results as foUows: 



Table 62. 



p. ct. 



DistiUed wstter 1,417 



Bog water 1,444 



Calcium sulphate 0.048 gram per liter 1,417 



Swamp water 944 



Calciimi sulphate 0.128 gram per liter 1,083 



Bog water and an equivalent calcium solution allow equal sweUing, 

 but the increase in swamp water is much less and also less than in the 

 equivalent calcium solution, to which may be attributed most of the 

 retarding effect of the swamp water. 



