How many grains of moisture in a pound of dry air?

google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=FWi&q=1+pound+in+grains&aq=f&oq=&aqi=g2g-m2">http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=FWi&q=1+pound+in+grains&aq=f&oq=&aqi=g2g-m2

JFGI :)