Thallium(I) sulfate

Thallium(I) sulfate, also known as thallous sulfate, is a chemical compound. Its chemical formula is Tl2SO4. It has thallium and sulfate ions in it. The thallium is in its +1 oxidation state.
Properties.
Thallium(I) sulfate is colorless, odorless, and tasteless. It is very toxic, though. It dissolves easily in water and is similar to potassium sulfate. 
Preparation.
It is made by dissolving thallium ore or thallium metal in sulfuric acid.
Uses.
It was used in rat poison, but since it is so similar to other chemicals, it poisoned some people and was outlawed. It was also used for some medicines before it was found that it was too toxic. It stops plants from germinating. It is the main source of thallium in the laboratory and is used to make thallium(I) sulfide. 
Toxicity.
Thallium sulfate, like all thallium compounds, is very toxic. This is because the size of the thallium ion is very similar to the size of the potassium ion. After it goes into the cells, it cannot be used like potassium is used and so kills the cell. It also gets absorbed through the skin. Eating more than 1/2 gram can kill. It gets deposited in the kidney, liver, brain, and similar places. It has been blamed for the extinction of the Brown Fish Owl.