What is the chemical composition of Turnbull's blue? I was studying qualitative analysis from this book and  I found some tests for testing the presence of the cation $\ce{Fe^{++}}$.

There was a test in which we add $\ce{K4[Fe(CN)6]}$ solution to a solution of a ferrous salt which results in the Turnbull blue precipitate. Now according to Wikipedia, the Turnbull blue and Prussian blue are the same compound, ie, ferriferrocyanide $\left(\ce{Fe4[Fe(CN)6]3} \right)$.

But the book says that Turnbull blue is ferroferricyanide $\left(\ce{Fe3[Fe(CN)6]2}\right)$ which kinda makes sense because we are adding ferricyanide to ferrous solution. 

I am preparing for an exam in which such questions can be asked SO I just want to settle this once and for all, which is wrong, Wikipedia or the book?
Though your textbook is right, Wikipedia isn't completely wrong as in aqueous solution, $\left(\ce{Fe3[Fe(CN)6]2} \right)$ gets converted and is in equilibrium with $\left(\ce{Fe4[Fe(CN)6]3} \right)$ (a redox change) and hence prussian blue and turnbull's blue are identical to look visually. But in a textual way, the naming is given as your textbook says, i.e. $\left(\ce{Fe4[Fe(CN)6]3} \right)$ is Prussian blue whereas $\left(\ce{Fe3[Fe(CN)6]2} \right)$ is Turnbull's blue.