12'2 PHILOSOPHICAL TRANSACTIONS. [aNNO 1786. 



XVIl. Observations on some Causes of the Excess of the Mortality of Males 

 above that of Females. By Joseph Clarke^ M. D., Physician to the Lying-in 

 Hospital at Dublin. Communicated by the Rev. Rich. Price, D. D., F. R. S. 

 p. 349. 



In the letter accompanying Dr. Clarke's communication. Dr. Price remarks 

 that, the observations which have been made on the laws that govern human 

 mortality prove, that the mortality of males exceeds that of females in almost 

 all the stages of life, and particularly in the earliest stages; and that this excess 

 prevails most in great towns, and all the less natural situations of human life. 

 The facts in these papers throw some light on this subject. Male foetuses re- 

 quiring more nutrition than female foetuses, because larger, and being also for 

 this reason more liable to injury in delivery, are brought into the world less per- 

 fect; and this happening more or less in proportion to the vigour and just for- 

 mation of the mother, it must happen most in those situations where the greatest 

 tenderness of frame and deviations from nature take place. The truth, in short, 

 seems to be, that any debility in either parent must affect most the production of 

 that sex which requires the largest and strongest stamina; and that such debilities 

 prevailing most in great towns and polished societies, the excess of the mortality 

 of males jnust also be greatest in such situations. And this Dr. P. reckons the 

 principal reason of a circumstance in human mortality, which, before he had re- 

 ceived these communications from Dr. Clarke, he did not so well understand. 



Dr. Clarke begins his first letter to Dr. Price by remarking that in his (Dr. 

 P.'s) very useful Treatise on Life Annuities, &c. " it has been observed," (vol. 

 1, p. 373) " that the author of nature has provided, that more males should be 

 born than females, on account of the particular waste of males, occasioned by 

 wars and other causes. That perhaps it might have been observed, with more 

 reason, that this provision had in view that particular weakness or delicacy in the 

 constitution of males which makes them more subject to mortality; and which 

 consequently renders it necessary that more of them should be produced, in order 

 to preserve in the world a due proportion between the sexes." And that he re- 

 marks, (vol. 2, p. 247) that " the facts recited at the end of his 4th essay prove, 

 that there is a difference between the mortality of males and females; but that 

 he must however observe, that it may be doubted, whether this difference, so 

 unfavourable to males, be natural; and that there are facts which prove that 

 there is reason for such a doubt." After stating a number of very satisfactory 

 facts of this kind it is remarked, that '^ the inference from them is very obvious; 

 that they seem to show sufficiently, that human life in males is more brittle than 

 in females, only in consequence of adventitious causes, or of some particular 

 debility which takes place in polished and luxurious societies, and especially in 

 great towns." 



