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ciently near the truth to demonstrate, in ge néral, the unhealthfulness of a marshy situation; and as the register from which they are derived is the only one, in such a situation, which I have ever met with, and Dr. Alexander's experiments may lead some to very wrong conclusions on this subject; I could not help thinking, that there would be no impropriety in sending you the account I have now given. If you think it of any importance, I shall be obliged to you for reading it to the Royal Society.

I cannot help taking this opportunity to add my wishes, that such registers of mortality as those published by Mr. Muret, were established in every part of this kingdom. We might then determine immediately every such question as that which has occasioned this letter; and know certainly what influence different airs and different situations have on the duration of life. Two ingenious physicians, Dr. Percival at Manchester, and Dr. Haygarth at Chester, have lately, with much zeal, promoted institutions of this kind; and a great deal of useful information may be expected from the accurate and comprehensive registers of mortality, which, under

a Dr. PERCIVAL has not succeeded at Manchester. But it has been seen, in the course of this work, that I have derived a great deal of information from Dr. Haygarth's register. Dec. 1781.

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their direction, have been established in these towns. But the instruction arising from these establishments cannot be complete, till they become universal. I am, Sir,

Your most obedient

and humble Servant,


Newington Green,
Dec. 21, 1773.




An Account of the NEW TABLES of the Duration of Human Life at Chester, Warrington, the Kingdom of Sweden, Stockholm, London, &c. inserted in the following Collection of Tables.

I HAVE in the second Essay in this Volume, p. 97, and in the Postscript to the 4th Chapter in the preceding Volume, p. 210, given an account of the improvement which was made in the former edition of this work, of the Table of Observations for Northampton, and of my reasons for wishing to discard the tables of the values of single and joint lives, founded on Mr. De Moivre's hypothesis, and substituting in their room the tables in the following collection.-I was farther enabled to improve this work, in that edition of it, by inserting


tables formed from a register of mortality established near twenty years ago at CHESTER. This register was formed on the plan proposed in the 2d Essay in this Volume, page 111, and, therefore, is more comprehensive than any register of the same kind that has been hitherto established.

Chester is a healthy town, of moderate size, where the births had, for many years, a little exceeded the burials; and the register to which I refer had the particular advantage of being under the direction of Dr. Haygarth, its founder as well as conductor, As it gives an accurate account of the distempers of which all the inhabitants die in every season, and at every age. it contains much physical instruction; but my views lead me only to take notice of that part of it which gives the law according to which human life wastes in all its different stages, both among males and females.

A summary of this part of the register is given in the introduction to the CHESTER tables, in the following collection of tables. Concerning these Tables it is necessary I should make the following observations.

The Table for females must be considered as particularly correct, because the number

* This able and ingenious physician has given another proof of his zeal to render his professional character as useful as possible, by instituting a plan, which he has been carrying on at Chester, for preventing the spread of the small-pox by infection, and thus gradually exter minating it.

of females born and buried in Chester are very nearly equal.On the contrary; the number of males born being about an 8th greater than the number buried, it follows that, in the table of decrements for males, the number of the living, and consequently the probabilities of living at every age, for at least 10 or 15 of the first years of life, must be given too low.

The expectation of a female at birth is, according to these tables, nearly 33 years; and of a male 28. The number of females, therefore, at Chester, is to the number of males as 334 to 28, or in the proportion of 8000 to 6771, which is the proportion discovered by a survey in 1774, when the females in this city were found to be 8016, and the males 6697 b.

These tables are farther confirmed by the proportion which they give of the number of males and females living under 15 to the whole number. This proportion is by the

It appeared from this survey (made with great care under the direction of Dr. Haygarth) that in 1774 there were in the ten parishes of Chester, including the suburbs, Families. Inhabitants. Males. Females.

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