The ;Ibsorl~;riico nic;ih~~i .~lmmts wxc ~~iack! with a Irltlgc pit mctcr using a glass ChXtIUdC -C~~~OliiC~ rCfCrCrlCC CkCtr~JdC SyYtCm. 5 g qlllll~~~i~~u?n. rCCtl;~td~lzCc\ fl Olll hCJt nltr'~JbCllzCllC, wcrc hcatctl to 70~ ant1 lo n11 fuming sulpliurlc acid (,200/;, SO,) -Ho" In a flask, the neck of which was covcrcd to prcvcnt absorption of molsturc from the air Sulplionation was continuctl for i 2 -2.1 Ii until a SIllid drop of the violet liquid withdrawn on a glass rod was complctcly soluble 111 water. J\ftCr cooling, the solution wab poured into 200 ml distillctl water. again allowed to cool, and flltcrcd. Tlic red filtrate was neutralitccl with conccntratcd sorlium hyclroxitlc solution to an incipient I3luc colour (quinalrzarin acts as an acidbnsc indicator at pn 5-G), and was made shghtly ncltl wlth tlllutc sulphurlc acid to prcvont hydrolysis of the sulphonic acid. About 4 vol. of 90% ethanol wcrc tlicn adclccl with vigorous stirrmg to i vol. of the ncutralizcd sulplionation mixture and the holution was filtcrcd to rcmovo prccipitatcd sodium sulphntc. The filtrate was evaporated unclcr rcclucccl presurc to very small volumo, and sodium qulnnll,z~rln sulphonatc was prcclpitatccl as a red solid by adding absolute alcohol. The cxtinctlon of this substance. compared with that of purrflcd qulnnli7nrin. suggcstcd that it was tho dlsulphonatc.