Carver worked on improving soils, growing crops with low inputs, and using species that fixed nitrogen (hence, the work on the cowpea and the peanut). Carver wrote in 'The Need of Scientific Agriculture in the South': "The virgin fertility of our soils and the vast amount of unskilled labor have been more of a curse than a blessing to agriculture. This exhaustive system for cultivation, the destruction of forest, the rapid and almost constant decomposition of organic matter, have made our agricultural problem one requiring more brains than of the North, East or West. Carver worked for years to create a company to market his products. The most important was the Carver Penol Company, which sold a mixture of creosote and peanuts as a patent medicine for respiratory diseases such as tuberculosis. Sales were lackluster and the product was ineffective according to the Food and Drug Administration. Other ventures were The Carver Products Company and the Carvoline Company. Carvoline Antiseptic Hair Dressing was a mix of peanut oil and lanolin. Carvoline Rubbing Oil was a peanut oil for massages.