turned on such that ambient air trapped in the aspiration tube until the valve is turned on will be entrained with the fluid to be mixed entrained air does not have any adverse effect on the operation of the invention but rather is believed to aid in the generation of microbubbles on the other hand its presence is not deemed to be critical it is believed that the additive fluid enters the reaction chamber 5 in a column with the mainstream liquid swirling around the column of additive fluid but whether or not the liquid is swirling it is known to be surrounding the column of additive fluid fluids not already mixed around that central column of additive fluid tend to move outwardly towards the mainstream liquid as the column expands and come into contact with a plurality of protuberances 7 that protrude into the core of additive fluid collision of the liquid with the protuberances 7 creates a number of vortices and low and high pressure zones whereby transient and incipient cavities inherent to the fluids being mixed are stretched and pulled upon exit from the reaction chamber 5 the fluids with stretched cavities enter a downstream zone 6 of the tube 2 defined by the absence of any protuberances where the stretched cavitation nuclei collapse or implode onto each other causing the phenomenon known as cavitation followed by the production of microspheres accompanied.