THANSACTIONS OK SI^fTION' F. 



807 



f 



In liiiHi tiiliirs the perfM^ntagoa run witli {,n'('at rcfriihiritv, and the rosults nro 

 verv>iiiiilii'' in tlic Iwo; so that, notwitlistaiidiiifr the ('ompanitivo sinallncss ol" ibo 

 numbers involvcil, tho results appear entitled to frreat confidence. 



In order t'l soivt! the second question proposed, and obtain tlio prohahility that 

 (imarriajre which Inis heen (diildless for several years will subsequently become 

 friiitl'ul, it is nci^i'ssary to tabulate the niarriajres according; to tlie year in -wliicb 

 the lirst cliilil was born. This is done in the loUowinfr table, wliicli relates to the 

 8U(jniairiajres <>> men under tliirty. It shows that 2U2 of these became fruitful in 

 the first year af'ier nnirriage, ili'A) in the second, 72 in the third, and so on, until we 

 come to a siii;ifle niarriafjre which became fruitful in the seventeenth yi>ar, after 

 whicli none Ijecani" Iruitful. l)eductin<,' from the total of 80(i the i'02 niarriafres 

 which hecaiiic fruitful in the lirst year, and the 4 wliich were dissolved Ity tlie 

 lieatli of eitli"" hu-liand or wife, we have 610 unfruitful niarriafres subsi.stin<,' at 

 ihe beiriiiiiinu- nf th(^ second year, of which 380 (or 70 per cent.) subse([uently 

 became fViiitliil. The lif^ures in the last column are obtained by division from 

 ihnse in ilie t-.\(i ])reviou8 ones, and fjive the probabi''ty required, which, we see, 

 stiwlily iliiniuish.'s to '20 per cent, at tlie be<.'iniiin,L'' "f tlie sixth year, 10 pur cent. 

 at the beL'innin;.' of the eleventh, and 1 percent, at the bej/inninp of the seven- 

 teenth, after wliirli it vanishes. 



I 



a K 



