An improvement in a sucker rod having an elongated metal body with opposed ends and threaded couplings positioned at each of the opposed ends comprises a thread form on the threaded couplings defining at least two concurrent helixes. A lateral opening connects the inlet with each passage beneath a removable plug closing the upper end of each passage, and valves are mounted in the housing each to close the passage beneath the lateral opening and thus beneath a ball on plug in the passage. The pulverulent material is introduced into the main gas flow, in a mixing zone, with a carrier gas flow whose net motion during introduction is essentially opposite to the main gas flow. The newsfeed is configured to display the content items in the contracted state upon the social network content item scrolling onto the user interface without respect to the content item being in an expanded state when previously displayed. A valve for use in a medicinal aerosol device comprising a sealing member comprising a crosslinked perfluorinated elastomer.