purified air

The boys were glad when the meal was at last finished and they were able to get out again into the sweet, sun-purified air.

It escaped; for when the sun reappeared, I saw my bird flying in the purified air, gayer than ever, with his heart full of song.

Inside, it was cool and bright, the chugging air-conditioners efficiently blasting purified air over the many work-surfaces.

We have now to devise a means of testing the action of such spontaneously purified air upon putrescible infusions.