/particle command - particles not showing

The /particle command does not appear to work, either i. in the Chat console, or ii. in a command block.

For example, one of the strings I tried was as follows:
/particle minecraft:test_bounce ~ ~2 ~

However, no particle effects show up.  I have also tried different syntax variations, as well as other particle effects, eg:
/particle test_bounce ~ ~2 ~
/particle minecraft:test_bounce 18 70 18 [using specific coordinates]
/particle minecraft:mobflame_emitter ~ ~2 ~ [using other particle effects]

(When I tried this in a command block, I tried both a <repeating/always active> block, as well as an <impulse/needs redstone> block.)

However, all yield the same result, ie no particles being displayed.
Any suggestions would be appreciated.  Thanks!