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 dry, hacking, cough is another story. This is one we do want to stop. It can be caused by allergies, dry air, a random tickle at the back of your throat that wonât go away, the aftermath of a cold, being in a dusty environment, etc. etc. For these we turn to demulcents, ingredients that soothe irritated mucous membranes and remove the irritant triggering the cough.