"H" was traditionally transliterated as "Г".
There is a tendency toward a phonetical transliteration now. For example, Irish physicist William Hamilton is known as Гамильтон in Russia. On the other hand, the name of British driver Lewis Hamilton is transliterated and pronounced as Хэмилтон. Nevertheless, if you see the letter "г" in a name you should pronounce "г". There is no exceptions, afaik.
BTW. Ломоносов, Ода: "...Что может собственных Платонов И быстрых разумом Невтонов Российская земля рождать."