On the nitrogen content of Russian comfrey

Russian comfrey の新鮮葉100g 風乾葉10g に水， 10%食塩水， 70% アルコーノレ液， 3.3%苛性ソーダ溶液， 0.3% 苛性ソーダ60% アノレコーノレ液を順次10 倍量宛加え，同じ操作を3回繰返しその合一＊液について窒素を測定した.各種溶剤可溶の窒素総量は全室奈量に対し新鮮葉は60%，風乾葉は47%で稿少ない.また試料の風乾lとより各種溶剤可溶窒素は総量lこ対し， 10%食境水可溶窒素量はその割合を減少するが， 0.3% 苛性ソーダ可溶窒素量はその割合を増加lする.純蛋白質においても同様の傾向がみられる. これは乾燥のため蛋白質に変性をきたしたもので試料保取の時期を異にしても同様な結果を示す.なおアンモニア態，硝酸態，アミノ態，アミド態，ペプチド態窒素をも測定し，特に硝酸と家畜Methemoglobinemia との関係を検討した.

The nitrogen content which is soluble in many kinds of solvents, in fresh and dried leaves of Russian comfrey was investigated. Harvest periods of Russian comfrey are in the latter part of May and in the early part of September. Ratios of H 20 and 0.3% NaOH soluble nitrogen are increased and 10% NaCl soluble nitrogen decreased in dried leaves compared to fresh leaves. These tendencies are observed in protein nitrogen fraction of dried leaves. The variation of solubility is considered to be caused by denaturation of protein. NH3-N, N03-N, NH 2-N, Amide-N, and Peptide-N are determined in dried leaves, and some considerations of these nitrogenous compounds, especially nitrate poisoning effect on livestock, are issued.