She made a journey to Friesland and was a convert to the doctrines of Labadie, but she was still devoted to her study and research. She was associated with the notable men of her time, and became the friend of the father of Rachel Ruysch. Although Madame Merian, who had taken her maiden name, was seventeen years older than the gifted flower painter, she became to her an example of industry and devotion to study. Madame Merian had long desired to examine the insects of Surinam, and in 1699, by the aid of the Dutch Government, she made the journey--of which a French poet wrote: "Sibylla à Surinam va chercher la nature, Avec l'esprit d'un Sage, et le coeur d'un Heros" --which indicates the view then held of a journey which would now attract no attention. While in Guiana some natives brought her a box filled with "lantern flies," as they were then called. The noise they made at night was so disturbing that she liberated them, and the flies, regaining liberty, flashed out their most brilliant light, for which Madame Merian was unprepared, and in her surprise dropped the box. From this circumstance a most exaggerated idea obtained concerning the illuminating power of the flies. The climate of Surinam was so unhealthy for Madame Merian that she could remain there but two years, and in that time she gathered the materials for her great work called "Metamorphoses Insectorum Surinamensium," etc. The illustrations were her own, and she pictured many most interesting objects--animals and vegetables as well as insects--which were quite unknown in Europe. Several editions of this book were published both in German and French. Her plates are still approved and testify to the scope and thoroughness of her research, as well as to her powers as an artist. Her chief work, however, was a "History of the Insects of Europe, Drawn from Nature, and Explained by Maria Sibylla Merian." The illustrations of this work were beautiful and of great interest, as the insects, from their first state to their last, were represented with the plants and flowers which they loved, each object being correctly and tastefully pictured. Most of the original paintings for these works are in the British Museum. In the Vienna Gallery is a "Basket of Flowers" by this artist, and in the Basle Museum a picture of "Locust and Chafers." The daughters of this learned artist naturalist, Joanna Maria Helena and Dorothea, shared the pursuits and labors of their mother, and it was her intention to publish their drawings as an appendix to her works. She did not live to do this, and later the daughters published a separate volume of their own. This extraordinary woman, whose studies and writings added so much to the knowledge of her time, was neither beautiful nor graceful. Her portraits present a woman with hard and heavy features, her hair in short curls surmounted by a stiff and curious headdress, made of folds of some black stuff.