The second process is one patented by Fritz Ullmann of Geneva, who utilizes chromic acid to oxidize the phosphuretted and sulphuretted hydrogen and absorb the ammonia, and this method of purification has proved the most successful in practice, the chromic acid being absorbed by kieselgiihr and the material sold under the name of "Heratol."
Ullmann died on the 12th of January 1865.
C. Ullmann's name of stilpnosiderite, from the Greek ariAirvOs (shining) is sometimes applied to such kinds of limonite as have a pitchy lustre.
Not much can be said in praise of the complete translations into the German language, neither of that of Ullmann, which has appeared in several editions, nor of that of Henning (Leipzig) and Grigull (Halle), all of them shallow amateurs who have no notion of the difficulties to be met with in the task, and are almost entirely dependent on Sale.
It was thought that it might be identical with hexaphenylethane, but the supposed synthesis of this substance by Ullmann and Borsum (Ber., 1902, 35, p. 2877) appeared to disprove this, although it showed that triphenylmethyl readily isomerized into their product, under the influence of catalysts.