April 19, 1789
The vines of John Stevens, which were trimmed late, not till March, bleed much; & will continue to do so until the leaf is fully expanded. It is remarkable, that tho’ this is the case while the trees are leafless, yet lop them as much as you please when the foliage is out, they will not shed one drop. Dr Hales was not acquainted with this circumstance when he cut-off a large bough of his vine at Teddington late in the spring; & it was lucky for science that he was not. For his sollicitude for his vine, & his various attempts to stop the effusion of the sap, led him step by step to many expedients, which by degrees brought on the abundance of curious experiments, & ended in that learned publication known by the name of Vegetable Statics, a work which has done much honour to the Author, & has been translated into many modern languages.