A nebulizer breathing system comprising: a nebulizer having a nebulizer head adapted to be received on a receptacle adapted to contain a liquid medicant to be nebulized; said nebulizer head including a first chamber having a closed top, enclosing sides and an open bottom adapted to receive for coupling thereto a receptacle adapted to contain a liquid medicant to be dispensed at a predetermined rate of concentration; said nebulizer head including a second nebulizing chamber carried within said first chamber at a position spaced from said closed top and extending downwardly therefrom; said nebulizing chamber having an open bottom adapted to pass entrained and nebulized liquid medicant outwardly therethrough; a nebulizing nozzle in fluid communication with said nebulizing chamber for creating a nebulized aerosol from liquid medicant coupled thereto; means for coupling a flow of nebulizing gas into said first chamber to said nebulizing nozzle and through said second nebulizing chamber carried within said first chamber; an aspirator tube having a first end positioned in fluid communication adjacent to said nebulizing nozzle, and a second end positioned to be received into liquid medicant contained within the receptacle; an auxiliary gas inlet port configured to introduce a supplemental gas into said first chamber extending into said first chamber at a position removed from the interior of said nebulizing chamber; said first chamber having a discharge outlet spaced from said open bottom of said nebulizing chamber and said auxiliary gas inlet port, for discharging liquid medicant entrained in said nebulizing chamber and the supplemental gas introduced into said first chamber through said auxiliary gas inlet port from said nebulizer; and a flexible tube coupled to said nebulizer discharge outlet and extending there from, said flexible tube having a discharge outlet for connecting the entrained liquid medicant discharged from said nebulizer discharge outlet to a patient interface; said flexible tube extending a length of at least approximately 45.7cm (18 inches) to provide a substantially uniform entrained liquid medicant discharge to the patient interface. a nebulizer having a nebulizer head adapted to be received on a receptacle adapted to contain a liquid medicant to be nebulized; said nebulizer head including a first chamber having a closed top, enclosing sides and an open bottom adapted to receive for coupling thereto a receptacle adapted to contain a liquid medicant to be dispensed at a predetermined rate of concentration; said nebulizer head including a second nebulizing chamber carried within said first chamber at a position spaced from said closed top and extending downwardly therefrom; said nebulizing chamber having an open bottom adapted to pass entrained and nebulized liquid medicant outwardly therethrough; a nebulizing nozzle in fluid communication with said nebulizing chamber for creating a nebulized aerosol from liquid medicant coupled thereto; means for coupling a flow of nebulizing gas into said first chamber to said nebulizing nozzle and through said second nebulizing chamber carried within said first chamber; an aspirator tube having a first end positioned in fluid communication adjacent to said nebulizing nozzle, and a second end positioned to be received into liquid medicant contained within the receptacle; an auxiliary gas inlet port configured to introduce a supplemental gas into said first chamber extending into said first chamber at a position removed from the interior of said nebulizing chamber; said first chamber having a discharge outlet spaced from said open bottom of said nebulizing chamber and said auxiliary gas inlet port, for discharging liquid medicant entrained in said nebulizing chamber and the supplemental gas introduced into said first chamber through said auxiliary gas inlet port from said nebulizer; and a flexible tube coupled to said nebulizer discharge outlet and extending there from, said flexible tube having a discharge outlet for connecting the entrained liquid medicant discharged from said nebulizer discharge outlet to a patient interface;