AN ENQUIRY Into the firſt Eight Years INOCULATION.
[5]IT is now about ten Years ſince the Inoculation of the Small Pox has been introduced a⯑mong us: Moſt contrary at firſt were Mens Opinions about it; ſome were confident the Practice would be of little Service, that the Di⯑ſtemper [6]could not be thus given, or if given, would not be leſs dan⯑gerous to the Patient; others, that it would be ſo beneficial, as that no one could die of the Small Pox, who thus underwent it.
The Writers of either Side were not a few, and many Reaſons both for and againſt the Practice were daily publiſhed.
However, the Inoculation went on, and the moſt impartial Judges were of Opinion, that how plau⯑ſible ſoever the Reaſons might be on either Side, that the Service or Diſſervice of it would beſt be known by obſerving the various Succeſs of it, and then comparing the Danger [7]of dying by the Inoculation, with the Danger of dying by the Small Pox in the natural Way.
To this End the learned Doctors Jurin and Scheuchzer have taken great Pains in getting in the Ac⯑counts of the Succeſs of all the Perſons inoculated for the firſt eight Years, as alſo of the Hazard Men underwent who had the Small Pox in the natural Way, and with Faith⯑fulneſs not to be called in Queſtion have publiſhed them.
By their Accounts it appears, that eight hundred and forty-five Perſons have received the Small Pox by the Inoculation, and that ſeventeen of them, or only one [8]Perſon in fifty hath been ſuſpected to have died by it.
That in the natural Way, out of eighteen thouſand two hundred and twenty-nine Perſons who have been ſick of the Small Pox, three thouſand and eight Perſons, or one in ſix, hath died of it.
Their Concluſion is, that if theſe eight hundred and forty-five Per⯑ſons had had the Small Pox in the natural Way, one in ſix of them might be reckoned to have died by it, that is, one hundred and for⯑ty, or rather, one hundred and for⯑ty-one Perſons; that is, one hun⯑dred and twenty-three, or one hun⯑dred and twenty-four more than [9]there died by the Inoculation, which Number of Lives they therefore think may actually be reckoned to have been ſaved by this Prac⯑tice.
It is very eaſy to obſerve, that the Advantage here ſhown is not the real Advantage, but a ſuppo⯑ſed one, it is grounded upon a Suppoſition, that all thoſe eight hundred and forty-five Perſons muſt have undergone the Diſtemper, a Suppoſition no otherwiſe true than that all Perſons whatever muſt un⯑dergo it, which, though indeed it hath been often aſſerted, is yet a Suppoſition, of which every Day's Obſervation in the Death of ma⯑ny Perſons who never had this [10]Diſtemper demonſtrates the Falſe⯑hood.
Paſſing by then this ſuppoſed Advantage, let us enquire into the real one, which can only be known by comparing the Loſs ſuſtained by theſe eight hundred and forty-five Perſons being inoculated, not with the Loſs out of ſo many Perſons who actually undergo the Diſtem⯑per, but with the Loſs out of as many who not ſubmitting to the Operation, take their Chance of having it in the natural Way.
Were Bills of Mortality pub⯑liſh'd for the whole Kingdom, as there are for London and Weſtmin⯑ſter, what this Loſs would be, [11]would eaſily appear, ſince by them it would be eaſy to ſee what Propor⯑tion the Number of thoſe Perſons who die of the Small Pox bears, to the Number of Perſons who die of all other Diſtempers; and, con⯑ſequently, in any given Number, how many would probably die of this Diſtemper, or what would be the Loſs out of the eight hundred and forty-five Perſons.
But ſuch Bills are only to be wiſh'd for; till we can have more Light in this Affair, we muſt be contented with ſuch as the London Bills afford us.
From a Table of Caſualties for twenty Years, publiſhed by the in⯑genious [12]Mr. Graunt, it appears, that out of two hundred twenty-nine thouſand two hundred and fifty-ſix Perſons, there died of the Small Pox ten thouſand five hun⯑dred and ſeventy-ſix, or one in twenty-one.
By a Table publiſh'd by Dr. Jurin for forty-two Years, one Perſon in fourteen died of this Diſtemper.
And by a Table publiſhed by Dr. Scheuchzer for eight Years, thoſe Years in which the Inoculation has been practiſed, one Perſon in twelve hath died of it.
Which of theſe Tables, or whe⯑ther any of them may be made the [13]Standard of the Mortality of the Small Pox, will not eaſily be deci⯑ded.
The Favourers of the Inoculati⯑on will think the laſt Table the moſt proper to be made the Stand⯑ard, and in regard to Perſons li⯑ving at London not unjuſtly, but the Enemies of it will think, and perhaps with as much Reaſon, that even the firſt Table repreſents the Small Pox too ſevere, to be made the general Standard of the Danger of it in the whole Kingdom.
Till a better Standard can be fix'd, it may not, perhaps, be great⯑ly amiſs, to ſuppoſe the laſt Table the Standard of the Mortality of the [14]Small Pox at London, and the firſt Table the Standard for the Kingdom in general, and ſo proceed to en⯑quire, what Benefit hath ariſen from the Inoculation, as each of theſe Tables is made the Standard of the Danger of the Small Pox in the na⯑tural Way.
By the firſt Table, when one Perſon out of twenty-one die of the Small Pox in the natural Way, then out of eight hundred and forty-five Perſons, there could only be reckoned to have died forty, and whereas there died out of the ſame Number by the Inoculation ſeven⯑teen, the Lives of twenty-three Perſons only can juſtly be reckoned to have been ſaved by this Practice.
[15]By the ſecond Table, when one in fourteen died of it in the natural Way, ſixty Perſons out of the eight hundred and forty-five would have then died of it, and forty-three Perſons more than there died by the Inoculation. And
By the laſt Table, when in the natural Way, one out of twelve died of this Diſtemper, ſeventy Perſons out of the eight hundred and forty-five would have died of it, and fifty-three more than by the Inoculation.
By all theſe Accounts, it ap⯑pears, that many Lives have been ſaved by this Practice; but that [16]the learned Gentlemen in reckon⯑ing one hundred and twenty-three, or one hundred and twenty-four Lives, ſeem to have been miſta⯑ken.
But though fewer Lives are loſt by the Inoculation than in the na⯑tural Way, yet as the Loſs of them one way is almoſt preſent, and in the other at ſome diſtance of time, it cannot appear unjuſt to make a further Deduction on this Account from the Number of Lives ſaved by the Inoculation.
Out of fifty Perſons inoculated at a certain time given, one of them is ſuppoſed to die of the Small Pox, and that preſently.
[17]Should theſe fifty refuſe to ſub⯑mit to the Operation, about four of them would die, and three Lives would be ſaved by the Practice.
But the time of theſe having the Small Pox is yet at a Diſtance; ſuppoſe at the time given for their Inoculation, the Lives of theſe Per⯑ſons to be each of the Value of thirty Years, or that theſe four Per⯑ſons one with another were to live thirty Years excluſive of the Dan⯑ger of their dying by the Small Pox; ſuppoſe now each of theſe Perſons were to live fifteen Years from the time given for their Ino⯑culation before they had the Di⯑ſtemper, it is plain theſe four to⯑gether [18]would have lived ſixty Years, the value of two Lives, before they died of this Diſtemper, which be⯑ing deduced out of the four Lives that are loſt out of the fifty in the natural Way, two only can be ac⯑counted to be loſt out of that Num⯑ber, and only one Life more than in the Way of Inoculation.
What Deduction is to be made on this Account out of the Num⯑ber of the Lives which are ſaved by the Inoculation cannot be determi⯑ned, unleſs we could firſt deter⯑mine, from a time given for their Inoculation, how long thoſe Perſons may be accounted to live, who are ſuppoſed to die at laſt of the Small Pox in the natural Way, and then [19]the Deduction would be plain and eaſy.
Should theſe Perſons then be ſuppoſed to live a ſecond, a third, a fourth, or ſixteenth Part of their Lives, let the Fraction, whatever it be, be multiplied by the Num⯑ber of the Perſons that are reckon⯑ed to die, as many Unites as the Product will be, ſo many Lives are to be deduced from thoſe ac⯑counted to be ſaved by the Inocu⯑lation.
When I conſider that few Per⯑ſons are inoculated but when the Danger ſeems near of their having the Small Pox, I cannot well ſup⯑poſe them to live longer than one [20]fourth of their Lives before they have it, and when I conſider that Perſons chiefly inoculated are very young Perſons, and that the Mor⯑tality of the Small Pox is moſtly among thoſe that are grown up, I am not inclined to think they ſhould have it much ſooner.
Let us then ſuppoſe that the Perſons who die at laſt of the Small Pox live one fourth of their Lives from the time given for their Inoculation, and the Deduction from the Number of Lives ſaved by the Inoculation will be as fol⯑lows.
According to the firſt Table, when forty Perſons out of the eight [21]hundred and forty-five die in the natural Way, each of theſe forty living one fourth of their Lives from the time given for their Ino⯑culation, together equal to ten whole Lives; thirty Lives only may more juſtly be ſaid to be loſt in the natural Way, and only thirteen Lives more than by the way of Ino⯑culation.
According to the ſecond Table, when ſixty Perſons die in the na⯑tural Way, theſe ſixty living each one fourth, or together fifteen whole Lives; forty-five Lives can only then be ſaid to be loſt in the natu⯑ral Way, and but twenty-eight more than by the Inoculation.
[22]According to the third Table, when ſeventy Perſons die in the natural Way, theſe ſeventy living each one fourth, or ſeventeen whole Lives, fifty-three Lives can only then be ſaid to be loſt in the na⯑tural Way, and thirty-ſix only more than by the Inoculation.
Were this Diſtemper not an in⯑fectious one, I ſhould here finiſh this Enquiry, and determine the Advantage to be on the ſide of the Inoculation. But it is moſt cer⯑tainly otherwiſe, ſo that it will be proper to inquire farther, how far the Inoculation of theſe eight hun⯑dred and forty-five Perſons may be ſuppoſed to have ſpread this Di⯑ſtemper, [23]and compare the Miſchief probably ariſing from the increas'd Infection, with the Miſchief that is prevented, or with the Loſs of as many Lives as are accounted to have been ſaved by the Practice.
Were theſe eight hundred and forty-five Perſons to take their Chance of having the Small Pox in the natural Way, it is eaſy to find out how many probably would have the Diſtemper and how many would eſcape it.
Upon the exacteſt Inquiry that could be made, and the beſt Ac⯑counts that have been given in, it appears that one Perſon in ſix [24]die, that hath the Small Pox in the natural Way.
In any given Number then ſix times the Number of the Perſons who are accounted to die of this Diſtemper, ſhould be accounted to undergo it, and the Remainder to eſcape it.
According to the firſt Table then, when out of the eight hundred and forty-five Perſons, forty only are ſuppoſed to die of the Small Pox in the natural Way, ſix times forty, or two hundred and forty Perſons only ſhould be ſuppoſed to have this Diſtemper, and ſix hundred and five Perſons to eſcape it.
[25]According to the firſt Table then, when out of the eight hundred and forty-five Perſons forty only are ſuppoſed to die of the Small Pox in the natural Way, ſix times for⯑ty, or two hundred and forty Per⯑ſons only ſhould be ſuppoſed to have this Diſtemper, and ſix hun⯑dred and five Perſons to eſcape it.
According to the ſecond Table, when ſixty Perſons are accounted to die, three hundred and ſixty Per⯑ſons ſhould be ſuppoſed to have this Diſtemper, and four hundred and eighty-five to eſcape it.
By the third Table, when ſeven⯑ty Perſons are reckoned to die of [26]it, four hundred and twenty-two Per⯑ſons ſhould be reckoned to have this Diſtemper, and as many to eſcape it.
The Miſchief then ariſing from the Inoculation of theſe eight hun⯑dred and forty-five Perſons, is the Miſchief that ariſes from ſix hun⯑dred and five Perſons having this infectious Diſtemper, who other⯑wiſe would probably have eſcaped it, or from four hundred and eighty-five, or from four hundred and twenty-two Perſons, as each of theſe Tables is made the Standard of the Mortality of the Small Pox in the natural Way.
The Queſtions then to determine, whether the Inoculation be of Ser⯑vice, [27]or not, according to the ſeveral Tables, are different, and theſe;
According to the firſt, Which is better, or of more Service to Man⯑kind, the ſaving of twenty-three Lives, or, according to the Deducti⯑on, of thirteen, or preventing the Miſchief which ariſeth from ſix hun⯑dred and five Perſons having this in⯑fectious Diſtemper?
According to the ſecond, Which is better, the ſaving forty-three Lives, or, according to the Deduction, twen⯑ty-eight, or preventing the Miſchief from the Infection of four hundred and eighty-five Perſons?
According to the third, Which is better, the ſaving fifty-three, or, if [28]the Deduction is to be allowed, thir⯑ty-ſix Lives, or preventing the Miſ⯑chief from the Infection of four hundred and twenty-two Perſons?
Theſe Queſtions may be different⯑ly anſwered, and the Practice accord⯑ingly either univerſally approved, or univerſally condemned, or perhaps allowed in one place, and condemn⯑ed in another.
To ſay there is no Miſchief to be feared from the increas'd Infections of ſuch a Number of Perſons would be a very bold Aſſertion, yet what the Miſchief probably to be expected is, is very difficult to determine.
The general, if not univerſal way of having the Small Pox, is account⯑ed [29]to be from Infection, and the Diſtemper now for ſome Years laſt paſt hath ſeemed to have been at a ſtand; that is, the Mortality of it ſeems neither to have much increa⯑ſed or diminiſhed, and the Number of Perſons that undergo it to have been neither much greater or leſs.
If theſe Propoſitions are true, each Perſon who has the Small Pox may be ſuppoſed the Cauſe of another Perſon's having it.
Unleſs therefore the Miſchief of Infection be leſs from a Perſon ino⯑culated, than from one who has the Small Pox in the natural Way, the Miſchief probably to be ex⯑pected from the increas'd Infection will be as follows.
[30]By the firſt Table, when from the Inoculation ſix hundred and five Perſons out of the eight hun⯑dred and forty-five have the Small Pox, who otherwiſe would have eſcaped it, theſe ſix hundred and five infecting or giving the Di⯑ſtemper to an equal Number, and one out of ſix of them dying ac⯑cording to the Standard of the Mor⯑tality of the Small Pox to thoſe that have them, the Miſchief from the increas'd Infection will be the Loſs of the Lives of one hundred Perſons.
By the ſecond Table, when four hundred and eighty-five Perſons have the Small Pox, who without the [31]Inoculation would have eſcaped them, the ſame Number will be by them infected, and the Miſchief will be the Loſs of the Lives of eighty Perſons.
By the third Table, when four hundred and twenty-two Perſons have the Small Pox, who without this Practice would not have had them; an equal Number will be infected, and the Miſchief from the increas'd Infection will be the Loſs of the Lives of ſeventy Perſons.
If theſe Suppoſitions may be admitted, the Inoculation for the firſt eight Years appears to have been of great Diſſervice to the World, ſince the Lives ſaved to the Per⯑ſons [32]themſelves inoculated fall very ſhort of the Lives loſt from the increas'd Infection.
Yet we have only now conſider⯑ed the Miſchief ariſing immediately from the firſt Infection from the Perſons themſelves inoculated; but the Miſchief ends not here, the Perſons thus infected may be ac⯑counted the Cauſes of a future In⯑fection, and the Small Pox with in⯑creas'd Strength may deſcend to our lateſt Poſterity.