The chemical laboratory is one of the most absorbing features of the Edison Estate. Here, workers helped Edison in his research on goldenrod as a source of natural rubber. Throughout the laboratory, where Edison conducted his last major experiments, all of his things are just as they were in his lifetime, including his "cat-nap" cot. Because of his deafness, Edison's sleep was undisturbed and relaxed him so much that 15 minute sleep to him was as good as is several hours to anyone else.