TRADERS OF HONGKONG: Some Foreign Merchant Houses, 1841-1899, by Dr Solomon Bard (The Urban Council, $51). FOR all the Li Ka-shings of today, Hongkong would not be what it is without the men who got the ball rolling. This book sheds new light on the origin of the hongs. Two wry quotes preface the work: ''There does not appear to be the slightest probability that, under any circumstances, Hongkong will ever become a place of trade,'' said R. Montgomery Martin (1846). ''The commerce of the world is conducted by the strong, and usually operates against the weak,'' said Henry Ward Beecher (1887). Dr Joseph Ting, curator of the Museum of History which produced the book, writes in his foreword of the resounding opinion of British prime minister William Gladstone: ''Hongkong except for the security of commerce is unnecessary.'' With these words ringing in the ears, the reader is off to a good start. The author deals efficiently and in brief with the history of trade with China, in particular the rise of Western ambitions to trade on a grand scale with her in order to redress the imbalance caused by the insatiable Western appetite for Chinese tea. The sole viable Western import to China proved to be opium, illegally pushed. We read of the ''factory'' system at Guangzhou used by the Chinese to attempt regulation of trade with the foreigners, and their ignominious failure to abort the import of opium as it began to drain the imperial coffers. And the inevitable wars that followed. Thus to the seizure of Hongkong as a safe haven for the traders. And thus to the point of the book - the biographies of the trading houses established in the new colony and how they fared in the rough and tumble of illegality, intimidation by British armed force and general skulduggery. The trading companies are listed and described under national headings, led by the British, followed by the Americans, Indians, Jewish merchants (some of the most important), Germans and others. And what a curious, devious, successful, terrifyingly industrious set of money-grubbers most of them were. Much of this concisely written information has not been readily available before and the book is, on that account, a valuable if tentative step in the right direction.