Experiment on Haemin Crystals:

Crystals are homogeneous solids, bounded by plane faces and having a geometric shape.


Preparation:

A small amount of dry blood is taken on a glass slide and crushed to a fine powder with the help of the fused end of a glass rod or with a needle. One crystal of common salt (NaCI) is added to it, which is also crushed to powder. The two are thoroughly mixed and two drops of glacial acetic acid added to it.

The mixture is covered with a cover slip and the slide heated over the flame of a spirit lamp. The reaction is complete with the beginning of boiling of the mixture and the slide is quickly removed from the flame.

The preparation is allowed to cool and examine under a microscope, initially under low magnification and then under high magni­fication.

Structure:


Haemin Crystals

Man:

Rhomboidal plates and prisms, often arranged in star-shaped clusters with round edges.

Rat:

Narrow plates with varying width to needles, blunt at both the ends.

Guinea pig:

Triangular plates often arranged in the form of square