696 



latex contains by tlie neutralization a small qnantily of potassinin 

 salts, that may somewhat displace the limit of the ranges. 



A second experiment related to the increase of the own acidity 

 of the latex, when left to itself. The latex nsed for this purpose 

 titrated, when left to itself undiluted, at 10 o'clock 0.026, at noon 

 0.030 and a( 1.45 p.m. 0.032 N. From the observations resulted: 



444 cc. 707, lalex, diluted at 10 o'clock with 5i cc. lO»/, HCl. 

 (i.e. mixture 0.1 normal, belonging in the upper pappy range of 

 transition, see Fig. 2): after one hour still liquid, but containing a 

 fair-sized lump of streaks, and after three hours a thick pap, fairly 

 well coagulated, with quite wiiite serum ; 



the same mixture, but prepared only at 12.30 p.m. from the 

 undiluted latex, was already coagulated, after being left to itself for 

 one hour, though the coagulum was still very soft. So the influence 

 of the higher own acidity of this latex was quite noticeable. 



43 cc. 40',, iaiex, prepared at 10 o'clock with 7 cc. 10" , HCl 

 (i.e. about 0.13 N, again in the middle of the upper pappy range 

 of transition, see Fig. 2) caused after one hour a small lump of 

 little skins, and was still liquid after (hree hours with a fairly 

 strong skin ; 



the same mixture, prepared at 12.30 was still liquid after one 

 houi' with a small lump of skins, which was somewhat larger than 

 in the above-mentioned mixture after one hour. So in this case the 

 difference was noticeable, though not important. 



It appears from these experiments, as might be expected, that, 



TABLE 1. 



