Sentence:  Subject to the limitations of this Act , the <WSD>Secretary</WSD> shall make stabilization payments to small domestic producers upon presentation of evidence satisfactory to him of their status as such producers and of the sale by them of newly mined ores , or concentrates produced therefrom , as provided in this Act . 
Meaning of the word marked with <WSD> tags:  the position of the head of the Department of the Interior