haversian spaces-spaces in bone formed by the enlargement of haversian canals. haversian system-a central canal containing capillaries and the concentric osseous lamellae around it occurring in compact bone.
Any donation to a political party, campaign, or action committee is non-deductible. Other non-deductible contributions are those to individual people, labor unions, business associations, for-profit schools, for-profit hospitals, foreign governments, and fees paid to associations or state or municipal governments.
Also, keep in mind that you can't write off a contribution to the extent that you get something in return. For example, if you buy a $50 ticket to a fundraising dinner at a church, but the cost of the dinner is $20, you can deduct $30.