684 

 TABLE I. 



Latex 



in the 



Lower 

 limit of 



Upper limit 

 first range 

 of 



Upper limit 

 liquid 



Lower limit 



second range 



of 



qiiaiitilies were olioseii in such a way tlial the final mixture was 

 always 50 cc, so that the latex-coiiceiilialion, at larger c|iiaiitities 

 of hydrochloric acid, decreased a iiltle, and thai the serial deter- 

 minations in tig. 2 are fonnd on slanting line.s. 



With a mixture with 70" ,, latex the result of' the examination 

 two hours after the addition of acid was (cf. fig. 2): 



After being left to itself for three hours, the coagulation of course 

 had proceeded furtiier; now 2'/, had become a pap, 2'/, n thick 

 liquid with a good many skins, 3 — 4'/, remaineii liquid, 5'/, was 

 softly coagulated. The mixtures in the strips of transition show a 

 furthej' advanced coagulation, but the true liquid mixtures remain 

 liquid, even after 24 hours. When it is left in open small cjlindric 

 glasses, a skin is formed at the surface, evidently by evaporation, 

 for in closed Erlenmeijer-flasks it was not formed. So the limits of 

 the ranges are somewhat displaced, according to the moment of 

 observation being delayed, but the phenomenon coagulated — liquid — 

 coagulated remains. It strikes us, that the transition at the lower 

 side of the liquid range is very acute; at the upper side however 

 much more gradual. The little skins formed on stirring, are partly 

 due to evaporation at the surface, or to latex, drying upon the side 

 of the glass; yet these skins point to i\ higher inclination for coa- 

 gulation, as such mixtures after 3 or 24 hours are coagulated further 

 than the purely liquid ones. 



