Flint tools

Birch bark was also used to produce pitch and tar. The pitch from Betulaceae bark has been found on arrowheads and flint tools from prehistoric ages and the pitch was probably a residue of the original adhesive [92,151,152]. Birch-bark pitch has also been identified in ceramic artefacts as an adhesive to coat, seal, or repair the inner surfaces of the vessels [90]. 

FIGURE 19 Flint tools. Axes, scrapers, and knives. Flint is a hydrated form of ciyp-tociystalline silica that occurs naturally as irregular nodules in chalk deposits. It is colorless and translucent when pure, but opaque and often colored when it contains impurities. When struck, flint breaks with a conchoidal fracture and the fragments formed have smooth, sharp edges. It is for this reason that prehistoric humans used flint to make tools. Since it also sparks when struck, flint was also used, until the eighteenth century, for lighting Are. 

Keeley, L.H. 1977. The function of Palaeolithic flint tools. Scientific American 237 108-126. Keeley, Lawrence H. 1980 Experimental Determination of Stone Tool Use A Microwear Analysis. 

Clactonian chopping tools are named after the British site of Clacton-on-sea, where there is also the earliest definitive evidence for wood technology in the prehistoric record—the wood was shaped using flint tools. 

The metal could not really be used for tools and weapons. It could certainly be forged into knives and arrowheads, but it was too soft. Stone-Age man might see a copper sword as a curiosity and a symbol of a new time, but for hunting and fighting he relied on the good old flint tools. 

Silica (Si02) and silicates have been intimately connected with the evolution of mankind from prehistoric times the names derive from the Latin silex, gen. silicis, flint, and serve as a reminder of the simple tools developed in paleolithic times (. i00000 years ago) and the shaped flint knives and arrowheads of the neolithic age which began some 20 000 years ago. The name of the element, silicon, was proposed by Thomas Thomson in... 

Flint Making tools Mainly silica Very compact sharp edges, conchoidal fracture... 

The supposed human remains were accompanied by flint implements and animal teeth, all of which apparently supported the early date attributed to the find. The flint implements were of a reddish color, matching that of local flints, but spectrographic analysis revealed that they had been artificially stained with chromium and iron salts below the layer of stain there was a white crust, whereas local flints were brown throughout. The animal teeth also seemed to have been "planted" at the burial site so as to suggest an early date the red-brown color of the teeth had also been artificially stained chromium and iron had been found when they were analyzed. A hippopotamus tooth, previously supposed to be contemporary with the tool carved from the elephant s tusk, was also stained with chromium and iron salts and contained little fluorine. 

Christensen, M., Calligaro, T., Consigny, S., et al. (1998). Insight into the usewear mechanism of archaeological flints by implantation of a marker ion and PIXE analysis of experimental tools. Nuclear Instruments and Methods in Physics Research B 136 869-874. 

Flint is the noncrystalline form of silicon and has been known to humans since prehistoric times. When struck with a sharp blow, flint would flake off sharp-edged chips that were then used as cutting tools and weapons. 

Tissue culture has been used to a limited extent for developmental toxicity studies of the studies that have used tissue culture systems, those using chick neural crest cells (Greenberg, 1982) and human embryonic palatal mesenchyme (Pratt et al., 1980, 1982) have been especially useful. In addition, the micromass teratogen test, first described by Flint Orton (1984), has been used as a screening tool, and this test has been used successfully for many years. This method uses cultures of limb and CNS cells. Rat cells are normally used, but mouse and chick cells have also been studied. Many different endpoints can be assessed. For a detailed description of the method, the validation studies and discussion of its predictive value, see Flint... 

More than 10,000 years ago, the first developments in the field of metallurgy were made in the Near East. Until that time man had used tools made of wood, bone and stone and with these materials he was able to meet all his requirements for devices and tools. An example from that period is the knife made of obsidian, a shiny black, brown or grey magmatically formed rock. The material is very finely crystallized owing to rapid cooling and is therefore often called volcanic glass. By beating it with another rock, you can break off extremely sharp pieces, a property shared with the flint that was mined in the south of The Netherlands in prehistoric times (fig.2.1). 

---