The world famous TRI-X, most black and white images shot over the last 50 years would probably have been on this emulsion, maybe, and then for it's 50th birthday Kodak gave it a facelift.

Here is what Kodak say about this legendary emulsion

KODAK PROFESSIONAL TRI-X 400 Film is a high-speed panchromatic film that is a good choice for photographing dimly lighted subjects or fast action, for photographing subjects that require good depth of field and fast shutter speeds, and for extending the distance range for flash pictures.