The first duty of a reviewer, so I am told, is to advise readers whether they need/should/will enjoy a book, and allocate a portion of their income to it. In this case, this poses something of a dilemma. On the one hand, I cannot seriously advise anyone I know to spend actual money on this work. It is, for reasons I shall elaborate on below, tedious and badly written, and it does not contribute very much to our knowledge of the history of science or forensics, to the public understanding of science, or to the presentation of science in literature. On the other hand, it perhaps has some value to anyone teaching the history of science in that it serves to remind us and demonstrate why some form of humanities training is as important to our discipline as a reasonable ability to understand the science under scrutiny.

The book claims to offer an in-depth look at Sherlock Holmes's use of science for his investigations. However, as it seems to be aimed at an audience that has barely heard of Holmes, including as it does a chapter introducing Holmes himself, Watson, Moriarty and other characters, it spends far too much time explaining the plots of the tales to which it refers to be able to offer anything ‘in-depth’. This approach sits oddly with the decision to make use of shorthand titles for the Holmes stories, so those readers who are unfamiliar with the works will constantly find themselves checking the index, while others will find much of the text unnecessary and tedious.

Further chapters cover influences (mainly Poe), the science used in solving cases, Holmes's chemistry and his use of other sciences. The chapter on the science used in solving cases takes a broad definition of science – and, indeed, of the verb ‘to use’ – covering Bertillon's anthropometry (never used), fingerprints (never used), footprints (used in cases where either exceptionally large, small or missing legs or feet serve to offer obvious clues), handwriting (to deduce age and sex of the writer), printed documents (i.e. differences between typewriters), cryptology and dogs (used in tracking). More familiar science is discussed in the next two chapters, but it becomes clear that this appears only tangentially in the stories and so these chapters offer a hotchpotch of otherwise unconnected episodes in the history of science. Asides that Holmes has been studying this or that prompt these excursions. For example, a section on the use of coal tar derivatives in the dye industry is based on Holmes's statement that he studied these in the period after his failure to die at the Reichenbach Falls. These chapters give the impression that Conan Doyle, while keen to make his creation appear scientifically adroit, was either unable or unwilling to write anything where real science materially assisted in the solution of a case. The question why Conan Doyle made this decision (was his opinion of his readership not particularly high?) would have made for an interesting study, but O'Brien is more concerned to perpetuate the characterization of Holmes as a scientific genius.

The book is not an easy read, being littered with non sequiturs, leaping from topic to topic, story to story, without pause for breath, making facile assumptions and generalizations at every turn. Strangest is the author's handling of sources. Perhaps it is a consequence of his scientific background (the dust jacket notes that he is professor emeritus at Missouri State University, and a little Web search confirms that his subject is chemistry), but he presents the opinions of other ‘Holmesian’ (Sherlockian in the US) writers in rather the same manner as he might present experimental data. However (and this does not sit well with his scientific background), he seems to take a largely uncritical attitude to all his sources, using an eclectic selection without apparently differentiating between between the carefully researched and peer-reviewed and the popular. So we have, for example, a comment that the ‘British scientific establishment had a great aversion to commercial aspects of their craft’ (p. 94), referenced with ‘U.S. News & World Report, April 30, 2001’, and the sentence ‘[t]hey were a group of “street Arabs”, a phrase used in Holmes's day to indicate homeless children’ (p. 42), which is sourced (unnecessarily, in my opinion) with one of a number of references to ‘Doyle and Crowder 2010’, a.k.a. Sherlock Holmes for Dummies.

While the author includes a lengthy bibliography, there is little evidence that he has read outside the Holmesian catalogue or utilized either general historical works or primary historical sources. On those rare occasions, his investigations were clearly superficial. For example, he is keen to argue against Isaac Asimov, who in a 1980 article labelled Holmes a ‘blundering chemist’, in part on the basis that in one 1892 tale he refers to his ‘analysis of the acetones’. O'Brien is pleased to counter this allegation with a reference to an 1885 chemistry textbook, showing that the class of substances now called ‘ketones’ was once referred to as ‘acetones’ – Asimov was evidently guilty of ahistorical criticism. However, a little further reading would have shown that Gmelin proposed the new name, ‘ketones’, as early as 1848, and that by the 1890s plenty of textbooks were referring to ‘ketones’ rather than ‘acetones’. It would seem, therefore, to take this rather silly argument to an extreme, that Holmes/Conan Doyle may not have been incorrect, but he was certainly rather out of date.

This example is typical of this really remarkably irritating book. Holmes is treated as a real person rather than a literary creation, much in the manner of fan fiction; indeed, it might best be described as ‘fan non-fiction’. The most interesting questions that might have been considered in this work – for example, how and why Conan Doyle chose to use science to assist with his characterization of Holmes; how the science represented in these tales related to the science and forensic practices of the time; and how they in turn were represented in other media, understood by the public and used by legal or investigative authorities – have been eschewed. Instead, the author has chosen persistently to bend his gaze on the trivial, the petty and the inconsequential. This is frustrating, as any serious analysis of Conan Doyle's inclusion of science in the Sherlock Holmes tales is sidestepped in favour of a rather muddled hagiography of Holmes as ‘scientist’.