In connection with the mention of this great man, this quotation from a letter written in his old age is copied from Mr. Emerson??s journal:?? ??Humboldt in 1843 congratulates his friend Karl Ritter, on the appearance of Zimmermann??s map of the Upper Nile. ??If,?? he says, ??a life prolonged to an advanced period, brings with it several inconveniences to the individual, there is a compensation in