vibratiunculæ

Nothing therefore is more unwarrantable, or more plainly shews the precipitant presumption of modern sciolists, than the familiar use of the general theory of aerial undulations in their attempts to explain the abstruse phenomena of nature (such as the communication of sensation from the organ to the sensorium by the vibrations of a nervous fluid, the reciprocal communication of the volitions from the sensorium to the muscle, nay, the whole phenomena of mind), by vibrations and vibratiunculæ.

1822, James Watt, John Robison, A System of Mechanical Philosophy, volume IV, page 476