1. corollary   opening or gap.   maker of maps.   proposition that follows without separate proof.   division into two classes.   Hint Half-n-half Clue   2. anemia   absence of contradictions or uniformity.   deficiency of red blood corpuscles.   collarbone.   triangular tract of mud or sand at river's mouth.   Half-n-half Clue   3. arboretum   drug or treatment preventing infection.   floating sheet of ice.   botanical garden where trees are studied and exhibited.   ability to produce desired effect.   Half-n-half Clue   4. catalyst   balance.   eye disorder leading to partial blindness; waterfall.   chemistry of changing baser metals into gold.   agent to speed up chemical reaction without it changing.   Half-n-half Clue   5. friction   ability of system to maintain stability.   conjecture or logical projection beyond range.   lizard noted for changing color to surroundings.   attrition by rubbing or disagreement.   Half-n-half Clue   6. analogy   parallelism or similarity.   druggist or chemist.   deficiency of red blood corpuscles.   giving off of gas bubbles or exuberance.   Half-n-half Clue   7. contagion   secret code used to encrypt messages.   state of being motionless.   deviation from center or oddity.   spread of disease by contact.   Half-n-half Clue