The recent influenza epidemic in Britain first appeared in Tyneside in the latter half of December, 1950, and is believed to have had its origin in Scandinavia {Lancet, 1951). Shortly afterwards there was an outbreak in Belfast, and almost concurrently in Merseyside, where the towns of Widnes and Runcorn, the centre of the chemical industry, were particularly affected. The epidemic received much publicity in the press, and this district was wrongly assumed by many to be the starting point of the outbreak in Britain. This paper is a brief account of the effects of the influenza epidemic in six chemical works in the Widnes and Runcorn area with a total population of 7,928. The processes in these factories are, in the main, continuous, and the factories must, at all costs, be prevented from closing down. The doctor in industry, and particularly in a chemical works, must always be on the watch for toxic manifestations related to plants or processes. However, in a chemical works such manifestations are relatively uncommon, and much of the doctor's time is devoted to the diagnosis and preliminary treatment of constitutional illness to which anyone is subject. My attention was drawn to the symptoms which appeared on December 18 in the six factories coming under my supervision. By noon in one of the factories 14 persons had reported to the medical department complaining of headache, aching limbs and back, dry throat, tracheitis, and pyrexia up to about 102?F. All appeared to be suffering from typical influenza. A rapid check proved that the cases were not all concentrated in one part of the works, but were coming from widely separated sections. The other five factories had the same experience and there was no doubt that the disease was rapidly reaching epidemic proportions. Little could be done to treat the patients in the factory medical departments, which became clearing houses for diagnosis and trans mission of patients exhibiting the typical symptoms. The factory car services were fully occupied in conveying patients to their homes and delivering notes from the works medical officers to the general practitioners. It is often impossible to distinguish clinically between influenza A and undifferentiated acute respiratory disease, as the Commission on Acute Respiratory Diseases (1948) found in their investi gation of an influenza A epidemic in military training camps in North Carolina. In the cases seen in our medical departments pyrexia had to be the chief factor in the decision to send a patient home or allow him to continue at work. Within a few days, no doubt because their own staff were also depleted, the local press reported the story of the influenza wave and its effects on the factory population, and this was soon taken up and expanded, in no uncertain terms, by the national press. It became headline news and drew the anticipated answer from medical authorities that, in fact, no epidemic existed. In spite of this, patients continued to arrive in ever increasing numbers at the factory medical department and, in turn, general practitioners became more and more hard pressed. The publicity continued and so alarmed the population both in and out of the factories that the figures for sickness absence rose alarmingly. Ordinary colds, minor pharyngitis, headaches and lumbago, were all labelled influenza, and the overworked practitioners with queues outside their surgeries could not possibly be accurate in diagnosis or certification. Their chief pre occupation was to decide which patients required their attention and which could look after them selves. It was quite impossible for them to visit all the sufferers, and, as one doctor observed, he was only able to prescribe on the telephone and follow up with a visit if the temperature did not subside in three days. The incidence steadily increased until the end of the first week in January, 1951, but, thereafter, the numbers fell steadily, while other parts of the country felt the impact of the epidemic and the health authorities agreed that the disease had indeed reached minor epidemic proportions. 91