The modern agronomist, however, takes all these twenty essential elements into consideration, and many so-called "complete" fertilizers contain at least sixteen to eighteen, if not all of the elements mentioned above. Cobalt, essential to animal nutrition, can also most economically be supplied through the soil, even though crops grow without it. As long as we have sufficient experimental research data that at least nineteen elements are invariably essential to all life, it stands to reason, that they at least must also be present in one way or another for the normal, or better the optimum growth of nut trees, and a crop of more nutritious nuts. Therefore, every time one of them is considered, all the others must also be borne in mind. It will neither prove difficult nor costly to experiment with them. It is a matter of finding the proper balance of everything essential for optimum nut tree growing. Indeed, to ascertain the true balance of all elements that are invariably essential to life, and their relationship to the elements which are variably essential, would quite naturally appear to constitute the quintessence of research still to be performed. We cannot control such essential factors as climate, weather, sunshine, but man can control the supply and adjustment of nutrients to trees, and it rests entirely with him to do so. There is one advantage a nut crop has over some other crops; it does not have to be harvested before fully mature. Nut crops obtain the benefit from elements that may be slowly assimilated during the season. The following experimental and historical evidence and opinions have come to my attention, and I record them for what interest they may have. Past experience is often discarded as too old, but many a time an experimenter was ahead of his time, and his work remained unrecognized, so that now some old references can be revived and presented as novelties. What the past ignored may indeed be due to the ignorance of those who did the ignoring. 1) The Chestnut Blight The chestnut blight, for instance, of a generation ago, may be re-examined in the light of the proceedings before a chestnut blight conference, held at Harrisburg, Penna., February 20-21, 1912. A chestnut extract manufacturer, a Mr. W. M. Benson[3], stated at the time that in his experience the best extracts were made from trees high in lime. "A blighted tree," he stated, "is simply a tree in the process of starving to death for lack of lime." Maps showed that the blight was worst where there was least lime, and that the chestnut trees died last in Tennessee, where soils are high in lime. Analysis showed that chestnuts contained 40% lime, an unheard of amount. That this high test may reflect a faulty condition is pointed out later.