Wow I never heard of that question before and Sadly I'm not sure how to answer that, but I'll give it a shot. I would say that there is only one true spirit and that is Jesus. God in the old testament was an Spirit and if you saw the spirit while you was alive you would die. Holy Spirit/Holy Ghost is still the same spirit that was God in the old testament, but through Jesus's death and ressurections this Spirit can come into our bodies and be seen without killing us.
The problem with this answer is that you are stting that Jesus is spirit and that God was manifest as Spirit but you have not explained what Spirit is. Doesn't the Bible give some explanation?