TENDENCY TO CALCULOUS DISEASES. 59 



district. But if we further remove the cases which occur in London and the 

 adjacent counties, with the respective population connected with them, we 

 shall have not more than 49 examples of calculus attaching to the whole re- 

 maining population of England and Wales, or 1 case only, for every 188,000 

 inhabitants, which is little more than one fifth of the proportion of London, 

 and of the Norfolk district excluding Norwich ; and only about one ninth of 

 the proportion of Norwich itself. 



The tendency of any particular class of persons to be affected with calculous 

 complaints, in the kingdom at large, must therefore be exceedingly small. But 

 if we take individuals between 14 and 50, (which is the most extended period 

 of active exertion in adult age,) the calculous cases will be still further re- 

 duced ; for though it appears by the population returns, that nearly one half 

 of the whole population of the kingdom, consists of persons between those ages, 

 yet the calculous cases belonging to this period of life, as inferred from the 

 Norwich register, are not quite a third of the total number. Under these 

 considerations, I feel some degree of difficulty in completely assenting to the 

 opinion which Mr. Copland Hutchison so ably supports*, of a sea-faring life 

 being remarkable for the comparative infrequency of urinaiy calculi -|-. 



In the Norwich as well as the London Hospital, the liability to calculous 



* On the Comparative Infrequency of Urinary Calculi among Sea-faring People. Medico-Clii- 

 rurgical Transactions, vol. ix. p. 443. 



f By the register of the London Hospital it appears, that of 265 cases of calculus, which have 

 occurred between the years 1761 and 1821, averaging 4^ per annum, 12 were of sea-faring persons, 

 making 1 in 22 of this class of persons, in the whole admissions. Of these, 2 were under 14 ; 4 be- 

 tween 14 and 20 ; 3 between 20 and 40 ; and 3 above 40. Mr. Borrett, an eminent surgeon of 

 Yarmouth, some years ago operated on a lad of 12 years of age, who was on his fishing voyage at 

 Yarmouth, from the North of England ; and the same gentleman assisted Dr. Tait, of the Naval 

 Hospital there, about the year 1809, in an unsuccessful operation on a sailor, who was brought on 

 shore, under great suffering, from a ship of war at that time lying in the roads. These are all the 

 instances with which I am acquainted, of the occurrence of calculus in sea-faring persons ; for the 

 register of the Norfolk and Norwich Hospital does not afford any evidence on the subject, as it is 

 only of late years, that the occupations of patients have been inserted in it. Without such an aid, I 

 should feel it to be impossible to speak from recollection, as to the occupations of public patients, 

 even if they had been known at the time of admission, which could be very seldom, and only inci- 

 dentally the case — The occurrence, according to Mr. Hutchison's interesting paper, of 6 cases of 

 lithotomy in 15 years, in a naval population of 160,000, will be in the proportion of .4 per annum, 

 or 1 in 400,000 persons. But if we put aside the London and Norfolk districts, as being more 

 than ordinarily liable to the complaint ; and comprise Scotland and Ireland in the caloilation, which 



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