[lake pigments]

Name: Tianhe with Wenrui
Date and Time:

2015.10.19, 10:10am

Location: lab
Subject:cochineal lake

10: 30 start heating the solution


10: 45 some bubbles come up
11: 07 stop heating -- 75`C
11: 16 60`C add the potash alum solution into it
11: 21 after adding, there is much foam on the surface and the solution looks like pink Cappucino! -- 54`C


It is perfect that the PH is between 6 and 7.

It is noteworthing that just after the lunch break there are two layers separated in the bottle clearly even we do not settle it overnight. And this is very different from the result of Anna and Marilyn's group although we have totally the same thing (for heating solution and dissovle potash alum) except the last procedure --- to pour alum solution into the heating solution. Wenrui did it extremely gradually --- drop by drop. And we even have different PH scale at last. It is possible that the procedure of adding matters a lot to the result, but it needs more comparative experiments to prove.