CYSTINE-CONTENT OF KERATINS

1) The determination was performed by Okuda\u27s iodine method (both macro and micro) and Folin-Looney\u27s colorimetric method. The results obtained by these two methods were?practically equal in regard to most of the keratins, but in the case of other proteins much larger results were obtained by the colorimetric method. This conclusion confirms the result already explained by Okuda. 2) The cystine c o ntent of . human hair differs in individuals, but it seems as a rule that the hair of the male is richer in it than that of the female, and in the same sex the hair of youths who are in the rapid growing stage is comparatively poor. 3) In the case. of other m a mmals the same tendency as descrived above regarding sex and age was also observed. Among mammals, the hair of monkies has as high cystine content as human hair. Among wools the coarse ones contain less cystine than the soft ones. 4) The feathers of Ayes contain generally l e ss cystine than the hair of mammals. In feathers the barbs contain more cystine than the shafts.1. シスチン定量は奧田氏の沃素法並に微量沃素法と FOLIN 及び LOONEY 氏の比色法とを並行せり。2. 沃素法と微量沃素法とは可成よく一致す。比色法はケラチンの場合には沃素法と一般に一致す。ゼラチンの如きに於ては過大の結果を與へたり。之れ尿酸試藥がシスチン以外の物質に作用したるに依るものなり。3. 沃素法に於て供試液無色透明なる時は指示藥を用ひずに其儘沃素酸加里液にて滴定する方終極點明瞭なり。然れども供試液着色せる時は又は曇天黄昏の時は指示藥として澱紛液を用ふるを便とす。4. 人毛中のシスチン含量は實驗の範圍に於ては13.15-15.5%なりき。男性の毛髮中のシスチン含量は女性の毛髮の夫れよりも常に含量大なり。10-20才の成長盛んなる時期にては, シスチンの含量は一般に少なし。シスチン含量は又個性に依り差あるが如し。5. 哺乳動物の毛のシスチン含量は10%前後にして8-14%に渡る, 猿類の毛が入類の毛髮に於けると相似たるシスチン含量を有する興味あり。6. 羊毛のシスチン含量は羊の種類に依り異なり, 普通7-9%の間なれど, ブラツクフェースドハイランド種の如き粗なる羊毛のシスチン含量は梢少なし。7. 哺乳動物の毛のシスチン含量は種類, 個性, 雌雄, 老若に依り差あり, 一般に雄に多く雌に少なく, 且つ老に多く若に少なき傾向あり。8. 鳥類の羽毛は哺乳動物の毛よリシスチン含量少なく, 羽枝 (Barbs) は常に羽軸 (Shaft) より多し, 又種類に依りシスチンの含量に差あり。9. 一般に下等動物程シスチン含量少なき傾向あり。10. 沃素法にては毛, 羽の如き試料は一瓦程用ふるを要すれど微量沃度法は0.1-O.2瓦にて可なり