Le Monnier, the eighteenth-century astronomer, observed Uranus twelve times, but decided that i t was a fixed star, not a planet. Thegrent discovery fell to Herschel, who identified L'ranus correctly in 1781. Historians have since decided Le Monnier's mistake was due at least in part to his hahit of writing measurements on scraps of paper-including a paper bag originally containing hair powder ( 1 ) . The keeping of good records is essential in a laboratory: a second example is provided by the case of Daniel Drnwbaugh v. Alexander Graham Bell. Rrll filed a patent application for the teleohone in 1875: Lhawhaueh sued. claimine the inven~~ ~ .~ tion for his own and at'court witnesses who testified he had discussed a crude teleohone with them. Rut this uersonal testimony did not convince the Supreme Court, which reiected Drawbaueh's claims lareelv on the basis of his inagility to single propezy dated piece of paper describing the invention (2). A th&d, contemporary instance of the importance of laboratorv notebooks is orovided bv the case of Gordon Gould, who as a young physkist filed application for a basiclaser patent in 1959. Gould failed to get the patent, which was awarded instead in 1960 to Charles Townes and Arthur Schawlow. Gould went to court, claiming he was the true inventor. His challenge was based in part on his research notebook which showed,amongother items, asketch,astatement of the main idea. and n derivation of the acronvm LASKR-~ ~ ~ .~ ~~ Light Amplification by Stimulated s mission-of Radiation (3). In October 1977, after a series of litigated oppositions, Gould was eranted a oatent for onticallv n u m ~ e d laser amplifiers. he world market has been estimated a i between 100 million and 200 million dollars. As these examples suggest, well-kept notebooks are valuable documents. Thev nrovide comulete, accurate records of . . ongoing work. In the event of litigation or contests for patent rights, thev are submitted as evidence. Thev serve the important rolk of corroboration should the reseGher or inventor have to Drove origin or substantiate statements and conclusions. he^ are vnluable documents to validate a company's claims to funds spent for research, particularly in support of ~ tax deductions. The uses of laboratory notebooks are not limited to legal issues. Thev are vehicles for organizine and focusine the thinking of the writer, as well as b2ng receptacles for deLailed procedural information that might not be available in highly compressed journal articles. Finally, they may serve not only the researcher or inventor but also the vublic. If ~ roue r ly . . maintained, they are a record of success and failure, a safeguard against error and carelessness in such important areas as the testing of drugs and chemicals.