[R] How to modify data frame stored in a list

[Honkit Wong]

Dear R community,
I have a question seems very simple but have trouble to do it. 
I have a list which stores many data frames. Now, I want to perform log10 on one column in each data frame in the list and save the value as a new column back to the original data frame in the list. How do I quickly do that with lapply function ?

Many thanks.