This is a novelty plastic desk thermometer made by the American drug company Lilly, to promote their antibiotic drug "Ilosone".
Its shape and colour takes the form of a large red and cream capsule. The capsule sits on a black plastic plinth imprinted at each end with "Lilly" and in on the front:
when your patient'stemperature is high REMEMBER 'ILOSONE'
As a thermometer it reacts well to temperature changes and seems to be fairly accurate. The temperature provides measurement in Fahrenheit, which suggests it was made for American use only.
It was probably made in the 1950s, as the drug Ilosone was released in 1952.
If you have any questions, just send an email to help@3bcshop.com.