Mr. Goodall called the attention of the meeting to the practice of slaking lime with salt water, now becoming very prevalent in Auckland. It was hardly necessary for him to state that, so long as this custom was in force, dry walls could not be expected in any buildings, however carefully other points were attended to.
Mr. Heale said that it was usual to attribute the efflorescence, so commonly seen on plastered walls in Auckland during damp weather, either to the use of shell-lime, in which a small proportion of salt might naturally be expected to occur, or to the sea-sand used in the preparation of the mortar. He could not but think that the proportion of salt in shell-lime would be very minute; and sea sand, even if taken wet from the beach, could not contain more than five per cent, of sea water. On the other hand, lime, during the process of slaking, would take up fully twenty-five per cent. of sea water, and in this way a very considerable quantity of salt would be introduced into the mortar; so large, in fact, that he should not have supposed that lime-burners would have had resort to a practice so obviously injurious to the quality of the lime if he had not himself seen salt water used.