230 



THE ALUMNI JOURNAL. 



STANDARDIZING OF NORMAL ACID BY 

 BORAX. 



By FRANCIS BERGAMI. 



More than thirty years ago, Th. Salzer recom- 

 mended the use of borax for the alkalimetric 

 measurement of acids, but his proposition at- 

 tracted very little attention until E. Rimbach* 

 published his work on the determination of the 

 atomic weight of boron. Since that time, sev- 

 eral other chemists have tried to introduce the 

 use of borax for the standardizing of normal 

 acid, but they all propose either methyl orange 

 or litmus as indicators for this purpose. Mr. 

 L. F. Kebler stated some time ago, before the 

 Chemical Section of the Franklin Institute, 

 that methyl orange proved to be of inferior 

 value in his hands, as well as in the hands of 

 other chemists. Litmus enables one to obtain 

 satisfactory results, but it requires a great deal 

 of practice, as the change of color in borax so- 

 lutions is not as distinct as could be desired for 

 routine work, especially by inexperienced work- 

 ers. I am, therefore, surprised that so little at- 

 tention seems to have been paid to the researches 

 of Robert T. Thomson, f on larmoid. 



Thomson found that larmoid, while its prop 

 erties as an indicator are nearly the same as 

 those of methyl orange, excels the latter sub- 

 stance by far in regard to sensitiveness, and 

 allows an absolutely correct titration of the al- 

 kali in borax solution. A double recrystalliza- 

 ation of the commercial c. p. borax yields a 

 strictly pure product, and by the aid of this and 

 larmoid as indicator, the standardizing of normal 

 acid becomes not only a very convenient, but 

 also an extremely accurate operation.— /owrwa/ 

 of the Franklin Instiiute. 



A NEW Method for Determining the 

 MEI.TING Point. 



In the course of legal analysis where 

 it became necessary to examine carefully very 

 small quantities of stearin and other candle 

 material upon pieces of clothing, and where the 

 quantity of material was so small, that the use 

 of capilliary tubes was impossible. VanLedden- 

 Hulsebosch devised the following method: He 

 laid some pieces of the cloth on which the fat 

 was detect d in a small aluminum capsule, and 

 floated this upon water in a large breaker. He 

 then heated this water bath very carefully, and 

 suspended in it a thermometer so adjusted that 

 only the upper portion of the water affected the 

 thermometer. Slowly raising the temperature, 

 he kept a close watch on the thermometer and 

 upon the grease under examination, and was 

 thus enabled to determine with considerable ac- 

 curacy both its melting and congealing points. 

 — Sci. Am. 



THE CHEniSTRY OF SACCHARIN. 



By Eckenroth & Koerppen. 



In a lengthy paper on some new de- 

 rivatives of saccharin, the authors state 

 that they have prepared the benzyl de- 

 rivative. 



CO 



CeH,/ \N.CHXeH3 



XSOs/ 

 by drying the sodium compound of sac- 

 charine at 150°, and boiling with excess 

 of benzyl chloride under a reflux con- 

 denser for 20 hours. The resulting com- 

 pound crystallizes in needles melting at 

 118°. It does not possess sweetening 

 properties. Benzyl o-amido-sulpho-ben- 

 zoic acid — 



COOH 



C6H4. 



SO.NH.CH^.CeHs 

 was prepared from the above described 

 body by heating for some time with alco- 

 holic soda. The sodium salt crystallizes 

 in rosettes and the barium salt is a fine 

 micro-crystalline pow^der. The authors 

 also prepared p nitro- benzyl saccharine — 



CeH./ \NCH,CeH,NO, 

 XbOo/ 



by heating to 200° a mixture of dry sod- 

 ium-saccharine and p-nitrobenzyl chlor- 

 ide. It forms fine needles melting at 1 76° 

 It is insoluble in water, slightly soluble 

 in cold and easily in hot alcohol. Several 

 other interesting nitro- derivatives are de- 

 scribed. The acetyl derivative — 



CO 



CcH^^ 



:N.CO.CH3 



SOo 



is prepared from sodium saccharine and 

 acetyl chloride. The chief product of 

 the reaction between sodium saccharine 

 and ethylene bromide is bromethyl-sac- 

 charine — 



CO 



CeH,( 



;N.C,H,Br. 



SO3 



* Fresenius' Zeitschri/t, 32, 526. 

 t Chem. News, 51, 18. 



It forms white glancing needles melting 

 at 96°, insoluble in water, but easily sol- 

 uble in the usual organic solvents — 

 Berichte. 



