William O. Douglas

“ Illinois has the final say as to the meaning of the ordinance in question. It also has the final word on the alleged conflict between the ordinance and the state Act. The determination which the District Court, the Circuit Court of Appeals or we might make could not be anything more than a forecast-a prediction as to the ultimate decision of the Supreme Court of Illinois. Here as in the Pullman case 'a federal court of equity is asked to decide an issue by making a tentative answer which may be displaced tomorrow by a state adjudication.' 312 U.S. at page 500, 61 S.Ct. ”

“ Respondent, a Michigan corporation authorized to do business in Illinois, sells milk to wholesalers and retailers in various cities in the vicinity of Chicago. By an ordinance passed on January 4, 1935, the City of Chicago required that milk or milk products 'sold in quantities of less than one gallon shall be delivered in standard milk bottles.' § 3094. Respondent sought a permit from petitioner Board of Health to sell milk in 'Pure-Pak' paper containers in that city. ”