1)S-precipitate (crude powder of Saliva-parotin) obtained from the secretion of the human parotid gland by acetone precipitation shows an action decreasing serum calcium level in rabbits. Since there is a linear relationship between the amount and the effect of S-precipitate, the func- tion of the parotid glands is able to evaluate by the study of the effect of S-precipitate on serum calcium level.
2) There is a close relationship between parotid function in the secretion of Saliva-par6tin, histological findings of the parotid and with finding on sialogram.
3) The.activity of S-precipitate obtained from healthy human saliva shows marked age differe- nce, being higher in younger and lower in older subjects.The activity of S-precipitate obtained from the patients with parotid inflammation is low, that from the patient of sialoangiectasis is almost normal, that from the patient of benign tumor is slightly lower, that from the patient of xerostomiasis is remarkably decreased and that from the patient of chronic atrophic rhinitis is normal or slight decreased.