Propolis season. Normally, it is dark brown in color, but it can be found in green, red, black, and white hues, depending on the sources of resin found in the particular hive area. Honey bees are opportunists, gathering what they need from available sources, and detailed analyses show that the chemical composition of propolis varies considerably from region to region, along with the vegetation. In northern temperate climates, for example, bees collect resins from trees, such as poplars and conifers (the biological role of resin in trees is to seal wounds and defend against bacteria, fungi and insects). "Typical" northern temperate
Wood glue to evaluate the mechanical resistance of wood joints with different glues: Wood glue Wood glue is an adhesive used to tightly bond pieces of wood together. Many substances have been used as glues. Animal glue, especially hide glue, was the primary adhesive of choice for many types of woodworking, including furniture and lutherie, for many centuries. It is manufactured from rendered collagen from the skins (hides) of animals. It is chemically similar to edible gelatin and is non-toxic if ingested. Hide glue is still used today in specialized applications: musical instruments (lutherie), for replica furniture, and for conservation-grade repairs to