William H. Burt was responsible for the actual proving of about 30 remedies. Generally working with crude doses as “heroic” provings. Burts provings include: Aesculus Baptisia Cactus grandiflorus Caulophyllum Collinsonia Dioscorea Hamamelis Hydrastis canadensis Iris versicolor Leptandra virginica Phytolacca Pulsatilla nutalliana (the native Pulsatilla of northwestern North America) Ustillago Veratrum viride (North Americas native Veratrum specie).