1939, shortly after the outbreak of the Second World War, and Mellanby authorized the project, allocating £250 () to launch the project, with £300 for salaries and £100 for expenses per annum for three years. Florey felt that more would be required. On 1 November 1939, Henry M. "Dusty" Miller Jr from the Natural Sciences Division of the Rockefeller Foundation dropped by to discuss funding Heatley's position. Heatley had fallen out with Chain, and had accepted a new position at the Carlsberg Laboratory in Copenhagen on a Rockefeller Fellowship, but due to the outbreak of the Second World War, he had decided to remain at Oxford. Miller arranged for Heatley to retain his fellowship. Instead of working for Chain, Heatley would report directly to Florey as his personal research assistant. As a bacteriologist, Miller was enthusiastic about the antibacterial project; he encouraged Florey to apply for a grant from the Rockefeller Foundation, and recommended to his headquarters that the request for financial support be given serious consideration. "The work proposed", Florey wrote in his application letter, "in addition to its theoretical importance, may have practical value for therapeutic purposes." Florey's application was approved, with the Rockefeller Foundation allocating US$5,000 (£1,250) per annum for five years. Florey's team already had a sample of penicillin mould; Campbell-Renton revealed that Dreyer had been given a sample of the mould by Fleming in 1930 for his work on bacteriophages. Dreyer had lost all interest in penicillin when he discovered that it was not a bacteriophage, but she had continued to cultivate it. The team developed techniques for growing the mould on a surface of liquid Czapek-Dox medium. Most laboratory containers did not provide a large, flat area, so glass bottles laid on their sides were used. Later, specially-made containers were fabricated. As the laboratory gradually became a penicillin factory, Florey hired six women to perform the cultivation and extraction work. It had to be carried out under sterile conditions; Abraham and Chain discovered that some airborne bacteria that produced penicillinase, an enzyme that destroys penicillin. Heatley and Chain tackled the problem of how to penicillin could be extracted from the mould. The liquid was filtered through parachute silk to remove the mycelium, spores and other solid debris. The pH was lowered by the addition of phosphoric acid and cooled. In this form the penicillin could be drawn off by a solvent. Initially ether was