The stress of this work again proved too much for Post's constitution, and a second breakdown followed in 1891. Post began a period of extensive travels in search of a cure, coming to take particular interest in the chemistry of digestion. After a period traversing Europe, Post visited the Battle Creek Sanitarium of Battle Creek, Michigan, a facility operated by John Harvey Kellogg (brother of Kellogg Company founder Will Keith Kellogg). Post has been accused of stealing several of Kellogg's recipes, including Kellogg's Caramel Coffee Cereal (Post's Postum), Cornflakes (Toasties), and Malted Nuts (Grape Nuts).