Editing Development of Darwin's theory (section)

===Health problems===
For the rest of the year, Darwin suffered increasing health problems, with fiercely inflamed boils, and in November Hooker left for [[India]].
Darwin returned his attention to family life and dissecting barnacles. In February 1848 the leader of British science Sir [[John Herschel]] wrote recruiting Darwin to a project drawing up instructions for sailors on scientific fieldwork, at the request of the [[First Sea Lord]]. Darwin spent five weeks writing a section for the manual explaining how any gentleman could "geologize".

That summer Communist revolution in France was followed by a massive Chartist demonstration in London, with the wealthy and the Queen fleeing to safety. Darwin's friends were mustered to defend the scientific institutions against the possibility of attacks by rioters who would have welcomed his secret theory. Continuing with the barnacles he found that what seemed like minute parasites were in some cases the minute males "& half embedded in the flesh of their wives they spend their whole lives", a "wonder of nature" not flattering to the Creation idea that God appointed the social system.

Darwin visited [[The Mount, Shrewsbury]] for the 82nd birthday of his father who was now seriously ill. He became desperately ill himself and returned home to be nursed by Emma who gave birth to their third son in August, then in November was devastated when his father died. Emma sustained him, and they read religious books together. In February 1849 he drew some comfort from [[Harriet Martineau]]'s new ''Eastern Life, Past and Present'', a travelogue of tombs with the message that Christian beliefs in reward and punishment were founded in heathen superstitions.