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This unusual commercial Doyle Pharmaceutical Company cover includes the standard Artmaster cachet on a business size window envelope.  Based on its contents, this commercial mailing was originally meant to solicit sales for their dietary supplement "Instant Meritene."  It is described as "The concentrated protein-vitamin-mineral food prescribed when ordinary foods must be supplemented."  Instant Meritene's price was only $2.19 per pound, however the mailing offered to send you one pound free of charge.  I imagine that this free offer has probably expired by now.  I wonder what this stuff tasted like?

The envelope also contained a letter written by Rachel M. Hayford from the Professional Service Department of Doyle Pharmaceutical Company to Dr. Juan S. Puentes in Atkinson Illinois, thanking the doctor for his interest in their recent mailing of First Day Covers.  The letter goes on to say that they have enclosed one of the covers for his collection.  I can only assume that the cover referenced is the one currently in my own collection.