The method employed in the determination of the tin was simply as
follows:
The contents of each can were emptied into a large porcelain dish, and
the condition of the inner coating of the can noted. After thoroughly
mixing the contents, fifty grammes were weighed off and incinerated in
a porcelain dish of suitable size. The residue was treated with a
large excess of concentrated hydrochloric acid, evaporated to dryness,
moistened with hydrochloric acid, water was added, and the mass was
filtered and washed, the insoluble matter being all washed upon the
filter. After drying the filter with its contents, the whole was again
incinerated in a porcelain dish and the residue treated as before. The
solution thus obtained was properly diluted and saturated with
hydrogen sulphide. After standing about twelve hours in a covered
beaker the precipitate was filtered off and the tin weighed as stannic
oxide.