PEOCBEDINGS, MAY. Xxi 



of this disease, why should persons employed in cleansing sewers be so 

 healthy as they are said to be, how, indeed, could any of them escape ? 

 These men in stirring up the foul deposits, inhale continuously the 

 nascent sewer-gas in all intensity ; for however well the sewer may be 

 ventilated it is clear the gas must exist there in greater proportion than 

 is possible in the upper air. It may be said these men have become 

 acclimatised to their surrounding, but as this suggestion cannot apply to 

 their first exposure to the gas before acclimatisation was possible, the 

 argument falls to the ground. I fear to trespass on the time of the 

 meeting by going more fully into this very wide subject, aud will 

 therefore only add that although I do not agree with those who think 

 the ultimate cause of typhoid has been discovered, many a report as to 

 the beneficial effect upon it of sanitation leaves no room for doubt as to 

 our proper mode of procedure. Our clear course is to do that duty 

 which lies nearest to us, i e., to thoroughly cleanse and purify all our 

 surroundings. When this is accomplished, although I think occasional 

 cases will still occur, the disease will probably be robbed of all, or most 

 of all, its terrors. 



His Excellency : Before calling on Mr. Johnston to reply I would 

 like to say a few words. In the observations I made at the last meeting 

 of this society I pointed out that I scarcely thought the public realised 

 how much they owed to societies of this sort. Nothing could better 

 exemplify this obligation than the paper we are discussing. (Applause.) 

 The duration of human existence, and the influences determining it, are 

 of the intensest interest to all, and men like Mr. Johnston, who, by 

 patient labour in their study, tabulate and intelligibly state the results 

 of observations, carefully recorded, as to the duration of life, are real 

 benefactors to their country — nay more, to humanity at large. 

 (Applause.) The science of statistics is a very difficult one — it requires 

 so much measuring and weighing of facts in their relation to each other. 

 But the common saying referred to by Mr. Johnston that " figures prove 

 anything," is only correct when they are not properly used. Now, Mr, 

 Johnscon has conclusively proved to us that in certain conditions you 

 cannot rely upon the death rate by itself as an index of the health of a 

 community. Does this prove that all statistics so based and accepted 

 hitherto have been wrong ? Certainly not. It only proves that this 

 index may be misleading where, from accidental causes, you have an 

 abnormal number of people of certain ages living in any particular 

 locality. In a perfectly normal state of society the number of persons 

 living at each year of age will depend entirely upon the rate of 

 mortality among them, and when this is so the general death-rate is the 

 readiest and most comprehensive test we can have of the health of the 

 community. But in the colonies we are not in a normal state, nor 

 shall we be for many a year to come, and migration, as Mr. Johnston 

 has shown, in their case clearly vitiates any general conclusions as to 

 the ^health of localities based upon the death-rate alone. Now, he has 

 shown us a very simple way of testing the health of the community. 

 He says, discard all deaths over 60 and you then get a trustworthy test 

 of the comparative health of the community. I agree with him in a 

 large measure, although there is much to be said for somewhat raising 

 the limit, and for the purposes of this test I should also eliminate deaths 

 of children under five years of age, as Dr. Parkinson proposes, respecting 

 which period I shall have something to say presently. But even so, you 

 must take the results with some qualification. People who emigrate to 

 the colonies are generally more healthy and strong than those of similar 

 ages who stay at home, and whether the death-rate among them in their 

 new home is greater or less than that of the colony is yet to be proved. 

 Now, as regards children under five, the death-rate at present every- 

 where is simply appalling. At the last meeting I said that the influence 



