The observed number of horizontal branch stars in eight globular clusters is combined with an estimate of the minimum time since the clusters last crossed the galactic plane and the assumption that stars lose M0 on the first ascent of the giant branch to derive the amount of gas which should be present in the clusters. It is assumed that all gas lost by stars since the last crossing of the galactic plane has been retained by the cluster. No estimate of the total cluster mass or assumption about the form of the mass function is needed in the above procedure. In M3 the lower limits to the mass of gas estimated in this way exceed the present observational H i + H ii upper limits, while in 47 Tuc the lower limit significantly exceeds the observational H I limit. As the time since a typical cluster crossed the galactic plane is likely to be significantly greater than the minimum time and as all the observations are upper limits rather than definite measurements, it appears that there is a discrepancy between the theoretical estimates and observations and some possible explanations of this result are discussed. If the numbers of horizontal branch stars are used in conjunction with estimates of the total cluster mass and the assumption that the initial mass function was of Salpeter type, the mass of the least massive stars at present in the clusters can be derived. It appears that stars less massive than M0 have preferentially escaped from the clusters.