TITLE: Example of a very simple math statement in old literature which is (verbatim) a pain to understand
QUESTION [99 upvotes]: As you know, before symbolic notations were introduced and adopted by the mathematical community, even simple statements were written in a very complicated manner because the writer had (nearly) only words to describe an equation or a result. 
What is an example of a very simple math statement in old literature which is, verbatim, a pain to understand?

REPLY [2 votes]: George Abram Miller (31 July 1863 – 10 February 1951) was an early group theorist whose many papers and texts were considered important by his contemporaries, but are now mostly considered only of historical importance. Much of his work consisted of classifying groups satisfying some condition, such as having a small number of prime divisors or small order or having a small permutation representation, or enumerating the possible finite groups which satisfy given conditions such as: the prime factors which divide the order, the orders of two generating permutations and their product; the types of subgroups; or the degree of a representation as a permutation group. Several papers investigate groups generated by two elements satisfying given conditions. For example he considered groups generated by two elements of order three whose product is of order four or three or six. He also considered permutation groups of small degree, groups having a small number of conjugacy classes, multiply transitive groups, and characteristic subgroups of finite groups. He found the list of all possible groups of order 1909 to 1919 inclusive. His Collected Works were published in five very large volumes. His style however, was very much aimed at using words, rather than symbols and formulas. No wonder that his collected works are so voluminous. He also use old group theory terminology (an element of a group is called an operator, a normal subgroups is called invariant, and more, etc.). See for instance this: