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.
1. The original virus that you have been fighting off may have moved further down your respiratory tract, triggering a dry cough, whereby nothing much comes up. This can become very painful, with repeated spasms of hacking coughs that arenât productive but just keep you awake and put your chest muscles through the wringer.