ABSTRACT
The concentrations of the main inorganic and certain organic constituents of bull seminal plasma have been examined. The average concentrations, in mg./100 ml., were:
Sodium and potassium were found to be inversely correlated, r = −0.86 p<0-001.
Calcium, chloride, fructose, citrate and total nitrogen were also strongly correlated (p<0-001), in such a way that a knowledge of the concentration of any one of the constituents enabled the average concentration of the other four in the sample to be predicted with considerable accuracy.
Sodium, potassium and chloride were estimated by standard chemical methods and with the flame photometer (sodium and potassium) and by electrometric titration (chloride). The applicability of the alternative methods of estimation, which require very small quantities of seminal plasma, has been examined and is discussed.
The freezing-point depression, Δ, of bull seminal plasma was-0-533, standard error of mean, 0-005.
The A’s of a number of laboratory and field diluents were also examined ; with two exceptions they were found to vary markedly from A for bull seminal plasma.
For the sake of brevity, the standard error of the mean, 
, is referred to as 
.
The raw data are available.
