The one problem with the book is that it is written long after the fact. This is reasonable for an autobiography, but I couldn't help feeling that the historical chapters were based on later knowledge, and so they tended to break up the flow. Towards the end as Sacks moves away from physical science to medicine, he seems a bit introverted - but again I wondered if this was a later analysis of the situation.
The book illustrates how much the attitudes to safety have changed. Anything called a chemical nowadays is considered dangerous. Now when I was young I bought some nitric acid and walked home with the bottle in my pocket. Sacks managed to get a small container of hydrofluoric acid, which is definitely nasty (although he never opened it).