A method and apparatus for dispensing precise quantities of reagents is disclosed including a positive displacement syringe pump in series with a dispenser, such as an aerosol dispenser or solenoid valve dispenser. A silver layer is added and annealed to withstand >450\xb0 C. Positioning tines may penetrate the patient to firmly locate the carrier in its proper position on the patient. The Hub also monitors subscriber data traffic to limit the amount of access consumed in a subscriber session, notify subscribers of a low balance, and the like.