586 1>R A. LOCKHART GILLESPIE ON 



Influenza. 



Sir Arthur Mitchell and Dr Buchan published two papers in the Journal of the 

 Scottish Meteorological Society in the numbers for 1889 and 1890, dealing in an 

 exhaustive manner with the two epidemics of Influenza which occurred in London, as 

 well as in the rest of the country, during the course of these years. By making use of 

 the mortality returns they deduced several very striking facts ; while, on further 

 comparing these returns with the weather conditions for periods both before and during 

 the epidemics, they found very little connection between the two. Their figures dealt 

 with the deaths due to or occurring with the prevalence of influenza, and they remarked 

 that some further statistics dealino; with actual cases of the disease would be of value. 



Influenza has been epidemic in this country on twenty-three occasions from the year 

 1510 to the year 1890. A considerable interval intervened between the great majority 

 of the attacks. 



List of Epidemics. 



1510 



1675 



1767 



1831 



1855 



1893 



1557 



1709 



1775 



1833 



1857-8 



1893-4 



1580 



1732-3 



1782 



1836-7 



1889-90 



1895 



1587 



1743 



1789-90 



1847-8 



1891 





1591 



1762 



1803 



1850-1 



1891-2 





It is worth noting that five epidemics occurred in the sixteenth century, only one 

 in the seventeenth, eight in the eighteenth, and, up to 1895, as many as fourteen in the 

 present century. Since the winter of 1889-90 we have passed through no fewer than 

 six distinct epidemics, varying in intensity. At no period from the beginning of the 

 sixteenth century until six years ago have there been so many attacks in so short a 

 time. From 1510 to 1889 the number of years which intervened between the different 

 epidemics averaged sixteen. In six instances only the attacks followed one another at 

 all closely, viz., in 1587, 1591, 1831, 1833, and in 1855, 1857-8. The occurrence 

 of influenza in epidemic form on so many separate occasions during the last six years 

 brings the number of recorded outbreaks since 1510 up to twenty-eight in 385 years, or 

 one in every 13 '7 years. The occurrence of six well-marked epidemics of influenza 

 during the last six years must have had a great influence on the incidence of disease 

 in the same period, when we remember the vigorous action of the poison on the 

 respiratory, the circulatory, and the nervous systems. From the statistics of the Edin- 

 burgh Royal Infirmary it is clear that sixty-eight weeks out of the 312 from 1st Oct. 

 1889, to 30th Sept. 1895, were marked by the prevalence of influenza in epidemic form, 

 that is to say, one week in every four and a half. In order that these figures might be 

 verified Dr K. M. Douglas kindly gave me the numbers of cases of this disease 

 occurring among the staff of the Post Office in Edinburgh for the same period. The 

 figures obtained from the Post Office are particularly valuable, as the total number of 

 those who could be attacked is known, the cases are all drawn from one class, and that 



