"Mercury chloride" can refer to two different chemical compounds:

* Mercurous chloride (Hg₂Cl₂) is also known as calomel. It is a white, odorless solid that is insoluble in water. It has been used in the past as a laxative, a diuretic, and an antiseptic, but it is now considered toxic and is no longer used medically.

* Mercuric chloride (HgCl₂) is also known as corrosive sublimate. It is a white, crystalline solid that is highly soluble in water. It is a very toxic substance that can cause severe damage to the kidneys, liver, and nervous system.

It's important to be aware that both forms of mercury chloride are dangerous and should be handled with extreme caution.

Here's a summary of important points:

* Both forms are poisonous and should never be ingested or handled without proper safety equipment.

* Hg₂Cl₂ (calomel) was used historically in medicine but is now considered toxic.

* HgCl₂ (corrosive sublimate) is highly toxic and should be avoided entirely.

If you have encountered mercury chloride, it is essential to contact a medical professional immediately.