STRUCTURE OF PROTOPLASM OF PARAMCECIUM. I I 



see that anions, or negatively charged ions, liquefy the protoplasm 

 of Paramoecium, cathions, or positively charged ions, coagulate 

 without any regard for the supposed chemical affinities of the 

 electrolyte. 



That we are not dealing with a specific chemical effect for each 

 electrolyte is still further shown by the fact that the activity of 

 each solution is roughly proportional to the valance of the pre- 

 dominant ion. Thus salts containing trivalent anions or cathions 

 are effective in much greater dilutions than bivalent or univalent 

 salts. All these facts are indicated in the accompanying table 

 which gives a list of the electrolytes used, their effects on the 

 physical structure of the protoplasm, and the greatest dilution 

 at which they are effective. The maximal dilutions can be only 

 approximate, as the action of identical solutions is not the same 

 on paramoecia from different cultures, because no two are exactly 

 alike in respect to chemical composition and osmotic pressure. 

 Especially is this true of the liquefying electrolytes, for, as we 

 have seen, in very dilute solutions it is frequently difficult to 

 determine the point at which the specific liquefying action of the 

 anion ends and the osmotic absorption of water commences. As 

 has been already mentioned, there are structural differences 

 between these two forms of liquefaction which enable us to dis- 

 tinguish between them with considerable accuracy, and the fact 

 of chemical liquefaction can be easily demonstrated by using the 

 liquefying substances in solutions about isotonic with protoplasm. 

 Of course no such difficulty arises with the coagulating solutions, 

 for at great dilutions the specific coagulating action of the cathion 

 must overcome the tendency for the protoplasm to be liquefied 

 through the entrance of water osmotically, and there is thus a 

 well-defined point at which the coagulation of the protoplasm by 

 the cathion ends and its osmotic liquefaction commences. 



TABLE II. 



Coagulating Solutions. Liquefying Solutions. 



/w/1,600 HC1, ;/i,6oo HNO S w/i,6oo NaOH, w/i,6oo KOH 



w/2,400 H,SO 4 w/l,6oo Ba(OH) 2 , mj 1,600 Sr(OH) 2 



w/40 KC1 w/40 NaCl, ;/4O NH 4 C1, w/4O NaNO 3 



w/640 MgCI 2 , w/640 CaCl 2 , mfiqo mfiqo Na. 2 SO 4 , m^o (NH 4 ) 2 C 2 O 4 



Ca(NO 3 ) 2 , w/640 Bad, ;/2,4OO Na 3 PO 4 , HI {2,400 Na 3 C 6 H.O 7 

 w/320 MgS0 4 

 i 1 1,600 A1 2 C1 6 , in 1 1, 600 Fe 2 Cl 6 



