Evalsan??? by the company Jan Dekker. (7) Polymers corresponding to the general formula (XVI) such as those described, for example, in French Patent No. 1 400 366: in which R29 is chosen from a hydrogen atom, a CH3O, CH3CH2O and a phenyl radical, R30 is chosen from hydrogen and a lower alkyl radical such as methyl or ethyl, R31 is chosen from a hydrogen and a lower alkyl radical such as methyl or