riot money

He had learned that the great disturbance amongst a portion of the guards was attributed to the failure in issuing a certain rate of allowance which was called riot money. […] Knowing also, that if they were ordered to march for foreign service no such increased rate of allowance was either given or expected, by what rule should it be granted when employed against their fellow-citizens? […] he wished to hear from his majesty’s judge advocate how long it had been the practice of the govenment to issue the increased allowance of riot money.