According to standard textbooks, the last episode of European New Age plague pandemic died out by 1720 in Marseilles. Despite this allegation, the pandemic continued in well-documented new outbreaks, which attacked and devastated Central and Eastern Europe throughout the first half of the 18 th century. At the beginning, military campaigns spread the infection out of the Ottoman Empire. Later on commercial goods took over this role via land or sea from Asia or out of the eastern Mediterranean region. Finally, the plague in Europe - except Russia and the Ottoman Empire - “died out” virtually by the end of the 18 th century. Explaining this, there many scientific reasons were suggested: 1. Oriental rat fleas as main vectors of infection could not tolerate any more the European weather conditions (although there were no virtual climate changes in the last 300 years). 2. Black rats that lived in close proximity to man, were being outplayed by brown rats living rather outside of human habitats; 3. There emerged less virulent Yersinia strains that caused natural human immunisation. In spite of these suggestions, which may have contributed to the success, joint civil and military health authorities blocked the plague indeed, as a result of disciplined and relentless law enforcement. In Hungary, respectively in the Hapsburg Empire, well-advised health legislation backed up the effectiveness of local authorities. Following the last great devastation in 1738-1740, the General Norm of Health Service - a voluminous decree - summed up by 1770 all the time honoured empiric rules of foregoing centuries. It can be excellently demonstrated, how exactly the empiric rules discovered a century later met scientific facts of physiology and microbiology.
At present mechanochemistry of sulphides appears to be a science with a sound theoretical foundation exhibiting a wide range
effectiveness in different areas of science and technology. For traditional application mechanochemistry is of exceptional
importance in extractive metallurgy of sulphidic ores where many technological processes have been developed. Metal sulphides
can be also utilized in emerging nanotechnology with application as advanced luminescence, optoelectronic, magnetic and catalytic
The changes in specific surface area and structure disorder of mechanically activated arsenopyrite were investigated. The
rate of nonoxidative decomposition of mechanically activated arsenopyrite was increased almost 10-times when compared with
nonoxidative decomposition of a non-activated sample. An empirical linear relationship was found (r=0.996) between the rate constant of decomposition and the ratio of specific surface to transmission of the absorption band
of arsenopyrite at
In this paper the reduction of lead and zinc sulphide by hydrogen is described. It has been found that the rate of formation
of elemental lead or zinc is favourably affected by mechanical activation of PbS and ZnS produced by intensive grinding. This
effect was observed in the region 678–1048 K for galena and in the region 851–1023 K for sphalerite. It has appeared that
disordering in the structure of both minerals results in the decrease in experimental activation energy.
The reduction of cinnabar (HgS) and stibnite (Sb2S3) by hydrogen was investigated. These investigations were performed in the temperature region 636–765 K for cinnabar and in the region 825–954 K for stibnite. It has appeared that the mechanical activation positively affects the thermal reduction of the sulphides. The thermal decomposition of HgS is accompanied by a change in mechanism taking place at 744 K. As to Sb2S3, the change in mechanism inthe investigated temperature region was not observed.
The changes of physico-chemical properties of mechanochemically pretreated (BaCO3 +TiO2 +PbO) powders were investigated. The values of apparent activation energy of BaTiO3 formation calculated by the Freeman and Carroll method decrease with milling time. The changes of precursors density may
be interpreted as a consequence of mechanochemical reactions during milling.