Chicago, Sept. 22. - Edson Keith, for forty years one of the prominent and influential citizens of Chicago, threw himself into the lake at the foot of Thirteenth street early Monday morning while temporarily insane, as a result of chronic dyspepsia and insorania. He disappeared f rom his home at 1906 Prairie avenue about 6 o'clock in the morning, but no indication of hia fate ■was discovered until Tuesday morning. Although search was made for the missing man all day Monday, the evidences of Mr. Keith's act were not discovered by his family until Tuesday, tut so conclusive were they that all hope was abandoned, and the lake is now being dragged for the recovery of the remains. While the family and friends of. the dead merchant had recently grown apprehensive regarding his physical con,dition, the discovery made Tuesday morning came with paralyzing suddenuess. In the light of it it was then re■called that Mr. Keith had been for some days so peculiarly depressed as to suggest mental troubles. His recent condition was recalled, and it was found that there was no room to doubt but what temporary insanity had followed his long months of sleeplessness and aggravated dyspepsia, and that the victim had found relief in the lake. Mr. Keith is best known through the ■Wholesale millinery and notion firm of Edson Keith & Co., of Wabash avenue and Monroe street, but he was also a member of Keith Bros., Wholesale dealers in hats at 237 Jackson street, and of Keith & Co. elevator, on the south branch. He was 63 years oíd and carne to Chicago in 1854.