[15/16.]
Id., 6th series, chapter 11.

[15/17.]
Conversations.

NOTES TO CHAPTER 16.

[16/1.]
Letter to his brother, 4th February, 1900.

[16/2.]
To his brother, 18th July, 1908. At this time the eighth volume of his "Souvenirs" had just appeared, and the ninth was in hand.

[16/3.]
Id.

[16/4.]
"Chimie agricole."

[16/5.]
To his brother, 10th October, 1898.

[16/6.]
Private letter, 30th March, 1908.

[16/7.]
Id.