Note 89 — I. Preservation of Objects composed of Inorganic Substances.

I have found that the amount of chlorine is smaller in winter than in summer. In the summer of 1894, 100 c.c. tap-water from the Stralau Waterworks often required 0·8 c.c. silver solution: but at that time stronger disinfectants were used on account of the cholera, and this may have caused the increase of chlorine; for since then, and even at the present time (winter 1898), 100 c.c. tap-water requires 0·5 to 0·6 c.c. silver solution.