I’m a new editor and am confused about the use of “condition”. If it is used to describe a strict experimental condition, is only “on condition that” can be used, but not “under the conditions of”? A senior editor tells me that the latter can not be used to describe experimental conditions, and if one really wants to use it, he/she should change the prep. into “on”. However, there is no such saying as “on the conditions that” in a dictionary(Longman). Looking forward to correct explanation.