1) Instilling agent 
A tea infuser is a device in which loose, dried tea leaves are placed for steeping or brewing, in a mug or a teapot full of hot water; it is often called a teaball or tea maker, and sometimes a tea egg. The tea infuser gained popularity in the first half of the 19th century. By the time of Queen Victoria, no respectable British household would be ...
• (n.) One who, or that which, infuses.
In·fus'er noun One who, or that which, infuses.