This idea from April 1963 is for a cap that measures powdered coffee.
No more guessing what the right amount of instant coffee should be for a standard-sized mug. With this idea, your instant coffee might be even more instant and better-tasting via perfectly measured amounts.
You simply replace the jar cap of your instant coffee with this screw-on dispenser. A slide on the side that you can pull releases exactly the correct amount of coffee into the dispenser through an aperture on the device. When you then push the slide the coffee drops down into the cup through an exit aperture.
An improvement to this device might be adjustable measures so that you could tailor the dispensed amount to your guest’s preferences for a stronger or weaker coffee.
This same idea could potentially be applied to dispensing other products such as herbs or spices, etc.