People lived without the safety net back when this stuff was written. Peoples' attitudes and perceptions regarding literally everything were completely different from those commonly held and accepted today. Yes, there have been major advances in science and medicine since this book was written and as a result many things within it are totally inaccurate - but that's not the point of buying this book.
I recommend that anybody with a slightly more than passing interest in 20th Century American history or general chemistry buy this book because you will find something within its many, many pages to truly enjoy. This book was written before the advent of the Harrison Act of 1914 (making some substances into illicit drugs for the first time in our nation's history) and Prohibition and then updated in 1927 after both were in full effect. This makes for some interesting and overt juxtapositions within the work. For example, the book contains a number of formulas and recipes for various kinds of alcohol and alcoholic beverages - the manufacture and consumption of which were just as illegal then as marijuana is now. It even goes so far as to tell you how to brew and distill different beers and spirits while staying within the legal alcohol content limits and then continues on to tell you how to do it properly and go well past the legal limits. In some instances it almost seems to make a case for breaking the law. For a particularly interesting read, try to find the 1907 unrevised edition and compare it to the 1927 edition. You may notice a few differences between them such as the recipe for laudanum (opium dissolved in alcohol with various other ingredients added to tradition and taste) which is relayed in the 1907 book but completely absent from that of 1927.
Overall, this book stands as a fascinating window into the common knowledge of medicine and science, the politics and the history of the early 20th Century in the United States. In addition to this, which is invaluable on its own, there is quite a bit of practical and correct information regarding everything from chemistry to construction within its pages. This book is so interesting, amusing and useful that I am personally stunned that I was able to obtain it for a grand total of $4.09 delivered to my front porch. Buy this book and prepare to sift through it patiently. You will be rewarded.