The Sound of the Color Red
I sometimes encounter at book fairs, trade shows and the like, book collectors who complain that "there's nothing new to collect." This often is after these collectors have come away empty-handed from such affairs, despite several hours spent wandering concrete floors.
Perhaps the subjects or authors they collect are subjects and authors other collectors also collect. This can lead to depleted bookseller inventories, to much higher prices than they are accustomed to (or willing to) pay, and so forth.
It is then that such collectors often seek what John Carter termed New Paths in Book Collecting--which is to say, there must be some interesting author or subject out there that no other book collector has yet latched on to--something that can be collected comprehensively, and relatively inexpensively, because no one else is yet collecting it. But what?
Hello...! Have you ever heard of libraries?! What about bookstores?! A few hours of wandering aimlessly about either of these will expose you to countless collecting possibilities.
Oops. "My bad!" I forgot that municipalities nationwide are shuttering their libraries. And are just as rapidly withdrawing their support for brick-and-mortar independent bookstores. So much for serendipity.
Or not. The Internet is brimming with serendipity, as anyone can vouch for who has ever wasted time on social networking sites like StumbleUpon. Consider, for example, the book collecting possibilities of a topic I recently came across in just such a serendiptious manner, synesthesia....
According to MedicineNet, synesthesia is a medical condition in which normally separate senses are not separate. Sight may mingle with sound, taste with touch, etc. The senses are cross-wired. For example, when a digit-color synesthete sees or just thinks of a number, the number appears with a color film over it. A given number's color never changes; it appears every time with the number. Synesthesia can take many forms. A synesthete may sense the taste of chicken as a pointed object. Other synesthetes hear colors.
Why collect books about this subject (assuming oneself or a loved one does not have this condition)? Well, for one thing, the printed literature is not that vast. The earliest reference I could locate was a pamphlet published in 1820. Most of the literature dates from the mid-20th century onwards. Not more than a few hundred titles altogether.
Moreover, the majority of these titles do not appear to be particularly expensive (a couple of typical examples are depicted below).
Articles about synesthesia might also warrant some space on one's bookshelves--many of these are readily available electronically (although the more scientific articles often require payment for access). As with books, the literature is not that vast...yet.
Of course, someone may already have beaten you to the punch, and is furiously collecting everything he or she can about synesthesia....