B t a u d i a g e r , Leupold:[Ja% 63 Praktion I : 0.1023, 0.1098 g Sbst. verbrauchten 0.3821, 0.4184 g J . .Us HJ 0.0113, O.OO;I g J. HJ durch Substitution: 94.3, 56.4 % Uoppelbiadungen. HJ durch Cyclisiening: 100.2, 99.9 yo Doppelbindungen. Fraktion P: 0.1012, 0.1089 g Sbst. verbrauchten 0.380;. 0.4103 g J . Als HJ 0.0056. 0.0099 g J HJ durch Substitution: 97.9, 96.2 y!, Doppelbindungen. HJ durcli Cyclisienmg: 100.9, 101.0 yo Doppelbindungen. Balata nnfraktioniert: 0.1078, 0.1052 g Sbst. verbrauchten 0.4216, 0.4019 g J . .Us HJ 0.0127. 0.0141 g J. HJ durch Substitution: 98.6, 95.2 yo Doppelbindungen. HJ durrh Cyclisiening: 104.9, 102.4 yo Doppelbindungen.

Varied views prevail as to the structure of the colloidal particles present in a rubber solution. According to Harries, Pummerer, and many others, these colloidal particles are formed through the association or aggregation of smaller molecules. According to Meyer and Mark they have a micellar structure, the micelles forming through the apposition of main valence chains. On the other hand, it was assumed by one of the present authors that the elementary particles in a colloidal solution of rubber are identical with the rubber molecules, these large, especially labile molecules being called macromolecules. Thus the existence of much larger molecules than any hitherto known was postulated. This view was confirmed by the conversion of rubber to hydro-rubber capable of forming colloidal solutions, and also by the pyrogenic decomposition of rubber. In order to decide definitely between the two conceptions, the stability of the colloidal particle in a rubber solution was studied by means of viscosity measurements at various temperatures as was done in the case of the polystyrols. If these colloidal particles form aggregates or if they have a micellar structure, they should decrease in size with increase in temperature, and this change should be evidenced by a diminution of the specific viscosity of the colloidal solution. On the other hand, if such a solution is composed of molecules, the specific viscosity at various temperatures is the same, provided that the molecules are not decomposed at higher temperatures. This line of research led to an explanation of the constitution of the colloidal particles in a polystyrol solution and was now applied to balata, since the latter is especially easily purified.

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