He estimated how many species of insects lived on each plant species in England, and then extrapolated that figure across the whole planet. âIf we say 400,000, we shall, perhaps, not be very wide of the truth,â he wrote. Today, scientists know the Westwood figure is far too low.
Symptoms: A chronic dry cough that's worse at night, disturbing sleep, and sometimes with wheezing and shortness of breath. Causes: An irritating night cough is often the first sign of asthma, especially in children, but you can develop it at any age. It's also a sign asthma is worsening or not being well controlled.
A number of medications can also cause dryness in the throat. One frequent cause of a dry throat is irritation. Breathing through the mouth instead of the nose when asleep or simply sleeping with the mouth open can expose the throat to dry air. This dry air irritates the membranes in the throat and can dehydrate them.