Mark Jackson is Professor of the History of Medicine and Director of the Centre for Medical History at the University of Exeter. His newest work, Asthma: The Biography, is a volume in our series Biographies of Disease which we will be looking at for the next few week (read previous posts in this series here). Each volume in the series tells the story of a disease in its historical and cultural context – the varying attitudes of society to its sufferers, the growing understanding of its causes, and the changing approaches to its treatment. In the excerpt below Jackson relays the story of Carlill v. Carbolic Smoke Ball Company.
On 7 December 1889, an American inventor, Frederick Augustus Roe, obtained a patent for a device that was designed both to cure and to prevent not only the deadly strain of influenza that was sweeping across Europe 
from Russia, but also a wide range of other respiratory complaints, including catarrh, bronchitis, coughs and colds, croup, whooping cough, hay fever and asthma. Sold from offices in Hanover Square in London for ten shillings, the Carbolic Smoke Ball comprised a hollow ball of India rubber containing carbolic acid powder. When the ball was compressed, a cloud of particles was forced through a fine muslin or silk diaphragm to be inhaled by the consumer. Boosted by testimonials from satisfied customers and endorsements from prominent doctors, Roe was sufficiently confident that the contraption would prevent influenza that, in several advertisements placed in the Illustrated London News and the Paul Mall Gazette during the winter of 1891, he offered to pay £100 to any person who contracted influenza ‘after having used the ball 3 times daily for two weeks according to the printed descriptions supplied with each ball’. As if to demonstrate the sincerity of his offer, Roe claimed to have deposited £1,000 with the Alliance Bank in Regent Street.
In November 1891, Louisa Elizabeth Carlill, the wife of a lawyer, purchased a Carbolic Smoke Ball in London and carefully followed the instructions for use. When Mrs Carlill contracted influenza the following January, her husband wrote to Roe claiming the ‘reward’ offered in the advertisements. Suggesting that the claim was fraudulent, Roe refused to pay and provided Mr Carlill with the names of his solicitors. In the resulting legal case, initially heard in the court of Queen’s Bench and subsequently reviewed by Appeal Court, the dispute did not revolve primarily around whether the plaintiff had used the device correctly or indeed whether or not she had contacted influenza; these issues were accepted largely as fact. Rather, legal arguments focused on whether the advertisement constituted a valid offer, rather than ‘a mere puff’, as Lord Justice Bowen neatly put it, and whether Mrs Carlill’s use of the smoke ball constituted acceptance of that offer. By deciding unanimously in Mrs Carlill’s favour, the English courts set a precedent regarding unilateral contracts that continued to inform the legal doctrines of offer and acceptance, consideration, misrepresentation, and wagering throughout the twentieth century.
While Carlill v. Carbolic Smoke Ball Company became a celebrated moment in legal history, it al