THE PARTNERSHIP METHOD OF RESEARCH. 275 



getting it published : he died at the age of seventy- 

 eight. 



Newton was born in 1 642, made all his great discoveries 

 between the ages of twenty and forty-five, and made no 

 more during the last forty years of his life ; this, however, 

 is fully accounted for by the circumstance that, at the age 

 of forty-five, he met with an accident which destroyed the 

 manuscript records of all his researches in chemistry, and 

 grief at this great loss affected his brain : he died at the 

 age of eighty-five, having occupied the latter part of 

 his life chiefly in publishing new editions of his works ; 

 he published the third edition of his great work, the 

 ' Principia,' at the age of eighty-three to eighty-four. 

 Shortly before his death he said, ' I know not what the 

 world may think of my labours, but to myself I seem to 

 have been only like a boy playing on the sea-shore, and 

 diverting himself in now and then finding a smoother 

 pebble or a prettier shell than ordinary, whilst the great 

 ocean of .truth lay all undiscovered before me.' Franklin 

 was born in the year 1706, and did not commence his 

 experiments until he was about forty years old : he died 

 at the age of eighty-five years. Humboldt lived to the 

 age of ninety, and was an investigator nearly the whole 

 of his life. Volta was born at Como, in 1 745 ; he began 

 to publish his numerous discoveries at the age of thirty- 

 nine years, and continued to do so until he was about 

 eighty years old. His great discovery of chemical elec- 

 tricity was made when he was forty-eight years of age, 

 and he completed his pile in the year 1800, having pre- 

 viously invented his electrophorus and electric condenser, 

 and become well known as a scientific investigator. Oersted 

 was born in 1777. The researches he made were exceed- 

 ingly numerous, and extended from the year 1801 until 



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