PRACTICAL HINTS TO NURSERYMEN 125 
22. Never put a new charge ina jar containing the 
old residue. 
24. Never put sulphuric acid in tin or iron vessels ; 
it will eat them up. Always use glass, earthenware, 
agate, or wooden vessels. 
25. Never lose an opportunity to caution persons 
about the danger attending the inhalation of this gas. 
