As the elderly Arab gentleman had a very rare type of blood, it couldn't be found locally, so the call went out. Finally, a Scotsman was located who had the same blood type. The Scot willingly donated his blood for the Arab.
The Arab sent the Scotsman an appreciation for giving his blood, a new BMW, five flawless one carat diamonds and $100,000, happy that his surgery could now go ahead.

A couple of months later, once again, the Arab had to go through a corrective surgery. His doctor telephoned the Scotsman who was more than happy to donate his blood again. After the second surgery, the Arab sent the Scotsman a thank-you card and a box of Quality Street Chocolates.

The Scotsman was shocked that the Arab did not reciprocate his previous kind gesture as he had anticipated.
He phoned the Arab and asked him: "I thought you would be generous again, that you would give me a BMW, diamonds and money, but you only gave me a thank-you card and a box of Quality Street Chocolates."
To this the Arab replied: "Aye, laddie, but I now have Scottish blood in me veins."