Page 428 - My FlipBook
P. 428
Fia. 167
Fin. 10". .\ pliotomicingiaph nf .sails ilial.vzid ti.ini llic saliva lo soparalo Ihcni from the gummj'
material with which thev are assoc-iatod. ami crystallized on n clean Rlass. When a eavit.v that has
heen wet with saliva has been dried by hot air, both these crystals and the gummy substances of the
saliva arc left on the walls of the cavity. They dissolve out after the filling has been made, causing
a lealc.
