If we look at 1 John 5:7-8 in the KJV, we find the following:
For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one. And there are three that bear witness in earth, the spirit, and the water, and the blood: and these three agree in one.
Compare this, for instance, to the ESV, which corresponds to all modern translations:
“For there are three that testify: the Spirit and the water and the blood; and these three agree.”