Umbilical cord blood banking
	During the 1930s  placental blood was adopted for use in transfusions.  A paper by Goodall et al (1938) begins with a viewpoint on childbirth teachings of the day:
					"The teaching that, if the blood is left in the placenta, placental detachment from the uterine wall is hastened, has never had any scientific appeal to us.  Consequently, it became a problem to be proved or disproved.  So at every birth, on our service, the clamp on the cut cord was released with the cord in a pendent position and the placenta was emptied."
		Further observations made by Goodall et al are of interest with respect to the pressure of blood left in the placenta after clamping.  They noted that during blood collection, the cord lay flaccid instead of quite turgid as was the case when waiting for delivery of the placenta with the clamp in place.  Separation of the placenta was not appreciably changed either, in elapsed time or completeness.  These authors commented on another discovery they made:
						"The blood pressure in the cord was great, projecting the blood frequently 3 feet distant, and the flow kept up a surprisingly long time."
				This was when they asked themselves, "Why waste all this valuable material?"   So they set about finding means to preserve the lost blood.  Many articles on how to collect, store, and use placental blood appeared within the next two years.
			Now, 70 plus years later, a whole industry has arisen to provide umbilical cord blood banking, with widespread marketing aimed at prospective parents.