Yearbook of Pharmacy 1871

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1871 edition. Excerpt: ... has recently repeated his statement that urea is obtainable from albumen by means of permanganate of potash, and has published details which seem to leave little doubt on the subject. The fact that urea is itself oxidisable by permanganate of potash will go a long way towards explaining the failures experienced by other chemists in their attempts to get it from albumen. Some results obtained by Chapman, Smith, and myself, in the course of investigations undertaken for the purpose of establishing the ammonia method of water-analysis, would seem to indicate that nrea exists ready formed in albumen; or rather that albumen is, like creatine, a compound wherein urea and something else are Joined together, with loss of the elements of water. When albumen is mixed with aqueous solution of caustic potash, and then dried-up in the oil-bath, it yields one-third of its nitrogen in the form of ammonia, the remaining two-thirds being obtainable as ammonia on boiling the dried-up mass with a solution of permanganate of potash. But, if the preliminary evaporation to dryness with caustic potash be omitted, the action of strongly alkaline permanganate of potash converts only two-thirds of the total nitrogen of albumen into ammonia. Now, a caustic alkali converts urea into carbonic acid and ammonia; but permanganate of potash oxidises it, so as to yield no ammonia, the nitrogen in this case making its appearance either in the state of gas or as nitric acid. So likewise in the case of creatine, one-third of its nitrogen is evolved as ammonia when permanganate of potash is employed, and m creatine one-third of the nitrogen is present in a form other than urea, while two-thirds of it exists as urea. It would, therefore, appear that one-third of the nitrogen in...