15 AUGUST 1992, Page 25

Waugh vindicated

Sir: P.T.A. Marlowe (Letters, 1 August) takes Auberon Waugh to task for stating that 'carbon dioxide is produced by vegeta- tion'. In fact Mr Waugh is quite right.

All green plants produce carbon dioxide continuously through respiration, as do ani- mals. The difference is that when a plant is exposed to light, photosynthesis starts, and uses its own carbon dioxide plus that from the atmosphere to help manufacture sug- ars, with oxygen generated as a useful by- product.

This explains why well-meaning night sis- ters in some hospitals still insist that flowers are removed from the patients' bedsides at night — because in darkness plants make more carbon dioxide than they consume, and use up more oxygen than they manu- facture. Perhaps Mr Waugh is still able to teach us a thing or two about science after all?

Jonathan Sleath

The Villa, Kingstone, Herefordshire