My right hon. Friend has no information about the extent of its use in hospitals, and it is too early yet to assess its use in domiciliary practice. Its chief advantage over gas-and-air in the domiciliary field is that the apparatus is more easily transportable. The costs of administration contain a number of highly variable factors, and we have not yet enough experience to make comparisons.
It is only recently that it came to be in general use by midwives, and it is a little too early to make an accurate comparison, but we are watching the matter very closely.