Year 5 had a very interesting visitor - 

Oswald of Oswaldkirk - a physician.

He tested a "sample", given to him by a sick child, to discover her illness.

First he held the sample up to the light to determine its 'thickness', then shook it gently to see if it contained any sediment. All was well! The colour of the sample was checked aginst his chart - had it been too dark, with an excess of black bile, the patient would need to make confession to the priest!

The final test was to taste the sample.

Hmm, it was FAR too salty which meant the patient had an excess of blood.

Only one cure - attach the leeches to draw off some blood!

No wonder she looks so worried!