"a German once wrote a book about a lemon peel..."

...[Rousseau] has, as he writes in the "Fifth Walk", deliberately forsworn the burden of work, and his greatest joy has been to leave his books safely shut away and to have neither ink nor paper to hand. However, since the leisure time thus freed up must be put to some use, Rousseau devotes himself to the study of botany, whose basic principles he had acquired in Môtiers on excursions with Jean Antoine d'Ivernois. "I set out to compose," writes Rousseau in the "Fifth Walk", "a Flora Petrinsularis and to describe every single plant on the island in enough detail to keep me busy for the rest of my days. They say a German once wrote a book about a lemon peel; I could have written one about every grass in the meadows, every moss in the woods, every lichen covering the rocks – and I did not want to leave even one blade of grass or atom of vegetation without a full and detailed description. In accordance with this noble plan, every morning after breakfast I would set out with a magnifying glass in my hand and my Systema Naturae under my arm to study one particular section of the island, which I had divided for this purpose into small squares, intending to visit them all one after another in every season." The central motif of this passage is not so much the impartial insight into the indigenous plants of the island as that of ordering, classification and the creation of a perfect system. Thus this apparently innocent occupation – the deliberate resolve no longer to think and merely to look at nature – becomes, for the writer plagued by the chronic need to think and work, a demanding rationalistic project involving the compiling of lists, indices and catalogues, along with the precise description of, for example, the long stamens of self-heal, the springiness of those of nettle and of wall-pellitory, and the sudden bursting of the seed capsules of balsam and of beech...

from A Place in My Country by W.G.Sebald