Method for preparing a compound comprising protonated glucosamine and
Cl.sup.-, Na.sup.+ and SO.sub.4.sup.2- ions, in which (a) glucosamine
hydrochloride and a stoichiometric excess of sodium sulphate are placed
in water, (b) the mixture obtained from the preceding step (a) is heated,
(c) the mixture is cooled, and (d) the solid present in the said cooled
mixture is recovered by filtration. Compound comprising protonated
glucosamine and Cl.sup.-, Na.sup.+ and SO.sub.4.sup.2- ions and having
the X-ray diffraction diagram of FIG. 1.
