The Hair of the Dog by Karl Sabbagh John Murray HK$136

Books such as The Hair of the Dog, a collection of 'scientific surprises', are a dime a dozen but worth the price because of the knowledge they impart, the temporary diversion they offer and the interest they spark in readers introduced to new subjects. However, they can also be infuriatingly superficial. Karl Sabbagh's book is guilty of being not only insubstantial but also of containing inconsequential articles. Some factoids are interesting, but immediately forgettable, such as that an Armillaria ostoyae fungus in the US, believed to be 1,500 years old, is the largest living entity on earth. But there are also potentially useful titbits, such as that cattle prefer to face north or south - handy should readers ever wonder in which direction to build their cowsheds (happy cows produce more milk). And then there is the matter of what is important. For instance, a piece about an American doctor, Peter Provonost, reveals he was one of Time magazine's 100 most influential people for 2008 simply because he devised a check list that resulted in fewer hospital infections: he persuaded doctors and nurses to wash their hands.