3/9/95 Dr.Shunwei Li, Chairman of Dept. of Neurology at PUMC, made a
     conjecture of thallium poisoning. But his guess was not put to
     scientific test and soon was denied by some famous toxicologists
     in Beijing. Since then, they had not consider that possibility.

,,,,

4/28/95 It was such a group international suggestion of thaliium
poisoning that made Zhu Lingling's parents brought some
samples for test to an independent agency, Beijing
Institute of Preventive and Occupational Medicine.

Bei called Xin Li about the test at 6 a.m. PST from Beijing,
saying that
it is thallium poisoning!!!

The test, conducted by Prof.Zhengyang Chen at Biological Monitoring
     & Trace Analysis Department of Beijing Inst. of Labour Hygiene &
     Occupational Diseases, showed that huge amount of thallium were
     found in Zhu Lingling's urine, blood, nail, hair and CSF. The level
in urine was 275 microgram/l, more than 50 times higher than the
normal value in Beijing (0~5 microgram/l)!