G UI ever, that they may with advantnge be employed iti distillation, and at- fordan agreeable spirit, resembling Brandy. It has indeed been as- certained by exi)erience, that such liquor, after having been kept a few months, was little inferior, in point of strength or flavour, to the best French Coniac. GREEN.— The following me- thod of preparing Brunswick Gred/i, a beautiful colour, in great request on the Continent for oil-painting, and in the manufadure of stain- ed paper, is inserted on the au- thority of M. Kastelkyn. He direfts shavings of cojjper to be put into a close vessel, and sprinkled ■with a solution of sal ammoniac. — The metal first unites with the muriatic acid, and is dissolved, when it is precipitated by the dis- engaged ammonia, with which it combines. The precipitate is then to be washed, and dried either in wooden boxes, or upon an expand- ed cloth : the liquid now remaining may be repeatedly employed as a solvent for fresh portions of sal anmioniac, till it be com[)letely sa- turated. M. Kasteleyn states, that three parts of such salt are .sufficient for two parts of copper, and that the result will be six parts of colour. — ^lliis beautiful pigment • is sold in Holland by the name of Friesland Green ; and it sometimes forms an article of exportation ; in which case it is generally adulte- rated with whitc-lrad. GUINEA CORN, or Holcus Sorghum, L. an exotic vegetable, growing on the coast of Africa : its stalks are large, compact, gene- rally attaining the height of 7 or 8 t'tct, and producing abundance of grain. — It may be easily raised in sheltered situations^ especially in f xliaustsd hot-beds and other loose GUM [229 soils, where its seeds should be sown early in the spring ; as the large flowery tops appear in June. — In Tuscany, Syria, and Palestine, the flour made ot this grain is mix- ed with other meal, and converted into bread 3 which, however, is ge- nerally brown, tough, and heavy. Hence the former is better calcu- lated for milk-porridge that is equally wholesome and nutritive. — The juice exuding from the stalks of the Guinea-corn, is so agreeably- luscious, that it affords excellent sugar, by a process similar to that adopted with the sugar-cane. The seeds furnish nourishing food to poultry and pigeons, as well as for horses and hogs. — Struve, a Ger- man writer on economy, states, that he obtained from this grain good vinegar by fermentation ; and, .on distilling it, a strong spirit. GUM, or GuM-SECUETiox, a disease in trees, arising from vari- ous causes, but mostly from inju- dicious pruning ; bruises, or inju- ries committed on the wood, or bark, by the hammer in nailing the branches against walls ; pinching the shoots by making the trellist s too tight, or by driving the nails too closely to the branches. It may also be occasioned by leaving the foot-stnlks of the fruit after this has been gatl'.ered: by careless- ly applying ladders ; and especial- ly where large boughs have been broken off, or inadvertently lop- ped. This distemper may be known before the gummy secretion ac- tually takes place, by the bark as- suming a brownish cast, that gi^a- dually deepens, till the gum -at length exuiles in the form of small blisters. As soon as any of these symptoms are perceived, Mr. For- syth direds the infefted part to be cut
