Yellows is a disease or malignant condition, it is not known which, virulent and contagious whatever it may be, and is the possession primarily of the region north of the Ohio and Potomac and east of the Mississippi. At one time or another it has been a cause of decline of the peach-orchards in every part of the region outlined. Epidemics of yellows have wholly obliterated thriving peach-industries which in some cases covered counties. The changes wrought by yellows come so quickly and are so final, so complete and so widespread in their consequences that the disease stands alone among the troubles of plants in the extent of its influence on the crop affected. Under somewhat better control now, its havoc is less than formerly, but in the past it has outdone all other accidents combined that have happened to peaches in America, including frosts, floods, drought, insects, fungi and injuries due to man and quadrupeds. The mystery of yellows in most of its aspects makes its known history all the more significant. We lack knowledge of what it is, or whence it came, nor do we know of any cure; we know only some of the circumstances and the terrible consequences to the peach. Yellows began its siege of the peach in the very beginning of commercial peach-growing in America. Much of the history of the peach is written in the hundred-years-warfare that has ensued. Judge Richard Peters of Philadelphia first described and gave name to peach-yellows. February 11, 1806, he read a paper "On Peach Trees" before the Philadelphia Society for Promoting Agriculture. In this paper we have the first clear account of yellows:[212]