ON ELECTROLYSIS IN ITS PHYSICAL AND CHEMICAL BEARINGS. 345 



pure water, and also in water in whicli had been dissolved 4'2 per cent, of commer- 

 cial gelatine. 



The proportions taken were : (a) 20 cc. of the salt solution diluted to 25 cc. 

 with water ; (b) 20 cc. of solution, in which 1*06 gram gelatine was dissolved, 

 diluted to 25 cc. The gelatine solutions were tolerably fluid at 30°, at 25° very- 

 thick and syrupy, at 24° the traces of fluidity were extremely small, and at 23-5° 

 the whole had jellied. 



The internal friction was determined by Sprung's ' method for the gelatine solu- 

 •tion containing 4'2 per cent, of gelatine, and was found to be, at 30'6° C, 2'271 ; 

 at 27"7° 0., 2-889, the internal friction of water at 0° being- taken as unity. At 

 24° the internal friction was infinitely great, i.e., the solution had gelatinised and 

 blocked the capillary tube. At corresponding temperatures the internal friction of 

 water is, at 30-5°, 0-4476 ; at 27-7°, 0-4547 ; and at 24°, 0-5171. The internal fric- 

 tion of the weak salt solutions employed can have difiered but very little from these 

 numbers. 



The distilled water showed a resistance of 60,000 ohms, while the gelatine solu- 

 tion averaged 300 ohms. It was therefore considered unnecessary to introduce a 

 correction for the conductivity of the distilled water present. Now as it is known 

 that all organic substances which do not possess well-marked acid, basic, or salt- 

 dike properties have extremely small conductivity, it may be concluded that gelatine 

 also, if free from salts, should manifest great resistance, and the high conductivity of 

 the gelatine is evidently due to the salts which it contains. 



Conductivity of Gelatine Solution, 



' PoggendorfE's Annalen, cliz.p. 1. 



