I assume you mean the original German book from 1888. This was scanned by Google and is available to institutions at Hathi Trust. I could no longer find it on Google itself. Probably it was taken down from the Google Books website, like so many other books that Google has scanned. A different scan of it is available at Scribd, for those who have joined Scribd. Since this scan is lower resolution, I assume that it came from the Digital Library of India. I have not been able to check the Digital Library of India itself, because nowadays their servers are almost always down when I try to go to them. However, it is probably there. Sorry that I do not have access to either of these scans.