怎么理解这里的what ,是从句还是副词
问题描述：
怎么理解这里的what ,是从句还是副词
he went off immediately to visit him, carrying with him in his pocket 【what remained of a bottle of medicine】 formerly prescribed for an indisposition of Mrs.Carlyle's.
分析一下语法
这是什么用法，怎样翻译
答
what用来补充前面的 in his pocket.把句子分开来就是：
He went off immediately to visit him.He carried remained of a bottle of medicine formerly prescribed for an indisposition of Mrs.Carlyle's with him in his pocket.
但是如果这样写的话太长和复杂,缺乏停顿.所以用what来补充之前比较清晰易懂.不对