VOL. XLVIII.] PHILOSOPHICAL TRANSACTIONS. 387 



It is tlierefore sufficiently demonstrated, that Dr. Halley's table ought not, in 

 M. de Burton's opinion, to be excluded from the class of those which " are the 

 only tables on which the probabilities of the life of mankind in general can be 

 established with any certainty ;" far from being comprised, in his severe judgment, 

 among those of authors, " whose researches, however ample, and the result of 

 long study, can aiford only distant approaches to the knowledge of the mortality 

 of mankind in general." 



M. de Burton begins his table of the probabilities of life with a term, which 

 precedes that of a year old, called zero d'age; and from M. Dupre's observa- 

 tions, assigns to it a duration of 8 years. M. K. first thought it an error of 

 the press; but there is no room for this doubt, after what M. de Burton says, 

 " We see by this table, that we may reasonably hope, that is, lay an even wager, 

 that an infant just born, or who has no age, will live 8 years; that an infant of 

 a year old, will live 33 years," &c. This little space of 8 years struck Mr. K. 

 because all the observations, which he knew, are very far from it. He had 

 therefore recourse to the source, to the observations of M. Dupre himself, and 

 found it was a mistake of M. de Burton; the mean life of infants of no age 

 being, according to M. Dupre's tables, 25 years and upwards; and, from the 

 observations of Justel, which Dr. Halley made use of, the mean life of a child 

 of no age is above 1^ years. 



M. K. thinks the subject not absolutely requires his ortering a word concern- 

 ing the nature of both Justel's and M. Dupre's observations. The remark has 

 not escaped the sagacity of Dr. Halley himself: it is, " that they want the essen- 

 tial; which is, the number of living persons, among whom the observations on 

 the dead are made." If M. de Burton had made the same reflections on M. 

 Dupre's tables, he would have found the irreparable defect of them, as well as 

 Dr. Halley did in Justel's observations; and he would doubtless have attended 

 more to the method proposed by Mons. Deparcieux. 



XXXVll. Abstract of a Letter from Father d' Incarville, of the Society of 

 Jesus, at Pehin in China, to the late Cromwell Mortimer, M. D., R. S. Seer. 

 Dated Pekin, Nov. 15, 1751. p. 253. 



The leaves and flowers of the varnish- tree, which he sent, came from the 

 province of Nan King. This tree is difltrent from that he saw in the king's 

 garden at Paris. The latter is the same with what he saw at Macao; which was 

 brought from Mississipi into France. There is not in Europe the tree, from 

 whose fruit the toeng yeou is drawn. It were to be wished they could raise it 

 there. The toeng yeou is an oil, or natural varnish, drawn by expression from 

 the fruits, which he sent, of which they make a very great trade in China. It 

 costs but very little, the pound weight being worth about 7 "i" 8 sols of our 



3d 2 



