1) Imperceptibly 1) Not substantially 
• (adv.) In an impalpable manner.
Im·pal'pa·bly adverb In an impalpable manner. 
impalpable, impalpably, impalpability 1. Not palpable; incapable of being perceived by the sense of touch; intangible. 2. Difficult for the mind to grasp readily or easily; such as, impalpable distinctions. 3. With reference to a powder, so fine that when rubbed between the fingers no grit is felt. 4. Impossible of being detected by touch; extrem...