This looks very interesting to see something in relations to Thomas Jefferson but it looks a bit broken up and ancient even though it was most likely 200-300 years ago. But, that is very interesting that chemistry was involved with Thomas Jefferson.
The Sabbath day is the 7th day (Saturday) of rest while the sabbatical year (or Shemitah) is the 7th year runs from September to September (Ex September 25 2014-September 13 2015). Sometimes it can Begin in September & end in October (Ex October 1, 1951 - September 19, 1952) or begin In September & end in October (Ex October 2 1902-September 21 1903) or it can even run from September to August (September 7 1811-August 25 1812) & Sometimes from August to September (August 31 1874-September 17 1875. The 7th shemitha opens up the jubilee (Yovel) which is the 49th year (7×7=49). The Shemitah ends on Elul 29 then that begins the ten days of awe which are days of repentance. Then on the last day the jubilee begins & it is a time of proclaiming liberty & freedom across the land. If you are a slave then you are free. The jubilee begun on September 13 1917 & it ended on Augest 24 1918. In that Time period Gernal Edmund Allenby marches into the land of Israel. The Ottoman empire collasped before the jubilee began & during the Shemitah. OOctober 1, 1951 - September 19, 195