691 



We traced tlie coagulalioii willi acetic acid once more by a 

 considerable number of determinations, viz. in the latex of botli 

 the above-mentioned groups of trees; in fig. 5 we have represented 

 the results, obtained with the 28 ° „ latex of the second group 

 (see ^ 4). The normality of acetic acid added is given in table 2 

 for the limits of the various ranges. 



TABLE 2. 



On comparing the.se tigures and fig. 5 with the results described 

 in ^ 3 — 5, we distinctly see the great difference in the distance 

 between the limits. A comparative review is given in § 7. 



In judging the above tigures one has to hear in mind, that the 

 plienoinena, in the sense in which we consider them here, are not 

 exactly the same as in plantation practice. So here we take as 

 lower limit of the range of coagulalion those mixtures, where a 

 colierent coagulum is formed after two hours, whilst with regard 

 to the coagulation at the plantations it is moreover required, that 

 the serum is clear or almost clear, and the coagulum sufTTicienllj 

 stiff' to be mangled. With undiluted latex tiie lower limit of the 

 range of coagulation, as it is described here (0.017 N or about 1 

 Gram acetic acid per Liter latex), will be lower than the amount 

 used in practice, if we wish to mangle a few hours after the coa- 

 gulation. With 50»/, latex (i.e. 1:1 dilutedUhe dose (0.030 N = 1.8 

 Gr. acetic acid per Liter is higiier, because witii diluted latex one 



