182 



THE ALUMNI JOURNAL. 



THE MOST RECENT WORK. 



Caffeine.— The recent synthesis of caffeine 

 from dimethyl urea and malonic acid, by Fisher 

 and Ach, has been described as being the first 

 synthesis of this useful compound. As a matter 

 of fact a synthesis, quite as elementary as the 

 one recently announced, has been long known. 

 Starting from guanine, C 5 H 5 N 5 0, xanthine, 

 C 5 H 4 N 4 2 , is prepared by the action of nitrous 



acid thus : 

 C 5 H 5 N 5 0+HONO=C 5 H. 1 N 4 2 +N 3 +H 2 

 Xanthine is converted into its lead compound, 

 which is methylated in the usual way. The 

 product is a dimethyl xanthine, or theobromine 

 isomeric with theophylline, the intermediate 

 body in the recently announced synthesis. The 

 constitution of xanthine is 



NH— CH=C— NH 



CO< | >co 



NH C=N 



and theobromine and theophylline are two iso- 

 meric dimethyl derivatives of it. Either of them 

 yields caffeine when further methylated, which 

 is, of course, trimethyl xanthine of the constitu- 

 tion 



N-CH 3 — CH=CN— CH 3 



CO< / >co 



N— CH 3 C=N 



Ammonium Thio-Acetate—k correspondent 

 of the Chemical News states that on using am- 

 monium thio-acetate in place of sulphurated hy- 

 drogen, as recommended by Schiff and Tarugi, 

 the precipitate of cadmium sulphide obtained 

 was reddish instead of yellow, and might easily 

 have been mistaken for antimony. Stannic 

 salts, again, gave brown-black stannous sul- 

 phide, instead of the usual yellow stannic sul- 

 phide. Finally, a tightly- stoppered flask con- 

 taining about 100 Cc. of the reagent burst, pre- 

 sumably by the pressure of gas given off. 



Saccharin in Beer.— It has been found by 

 Gaulter (Zeit fur Anal. Chem.) that the fluor- 

 escence produced by solutions of saccharin 

 treated with sulphuric acid in the presence of 

 resorcin is also produced by the resin of hops. 

 In order to detect the saccharin in beer, he 

 proposes the following test: 



The beer is first evaporated to a syrupy con- 

 sistence acidulated with a few drops of hydro- 

 chloric acid, and then treated with alcohol to 

 precipitate thedextrins. The alcoholic solution 

 is again evaporated to a syrupy consistence and 

 agitated with ether. 



The ether is then evaporated, and the extract 

 which consists of hop-resin and saccharin is 



treated with boiling water, which dissolves the 

 saccharin, which may be detected by its sweet 

 taste. 



Fluorine and Argon. — M. Henri Moissan 

 recently read a note at the Paris Academy ot 

 Science, says Ch. and Dr., concerning the ac- 

 tion of fluorine on argon. During his recent 

 visit to Paris, Prof. Ramsay left a tube of 200 

 cc. of argon gas with M. Moissan. The latter 

 has caused fluorine to react on argon, in a 

 platinum apparatus closed by sheets of trans- 

 parent fluorspar, which was shown to the meet- 

 ing. He was able to ascertain that at the or- 

 dinary temperature no combination took place. 

 M. Moissan also caused boron, titanium, and 

 uranium, prepared in his electric furnace, to re- 

 act on argon, but obtained no combinations, al- 

 though these simple bodies unite with nitrogen 

 with great energy. M. Moissan comes to the 

 conclusion that of all the simple chemical bodies 

 argon isolated by Lord Rayleigh and Prof. Ram- 

 say is that which presents the greatest inertia. 

 It is the opposite of fluorine, which is the most 

 active body that exists.— Pharm. Jour. 



Paucine is the name given to an alkaloid iso- 

 lated in Merck's Laboratory from the Pauco 

 nut. (Pentaclethra macrophylla.) It occurs in 

 yellow scales, is soluble in hot water and alco- 

 hol, but is insoluble in ether or chloroform. 



The hydrochloride gives with ferric chloride 

 a dark-green color, while the alkaloid shaken 

 with soda solution colors the liquid brownish- 

 red, which gives place to a dark-red color on 

 standing. 



Glucose in Honey. —Glucose invariably con- 

 tains small quantities of dextrin, whilst honey 

 does not. If a sample of honey is suspected of 

 adulteration with glucose, one part of the sam- 

 ple is mixed with two parts of water, and 

 warmed with two per cent, of animal charcoal. 

 Ten cubic centimetres of the colorless liqid are 

 then poured into a test tube, and absolute alco- 

 hol poured in. If at the zone of contact a 

 turbidity appears, dextrine, and consequently 

 glncose, is indicated. — Repertoire de Phar- 

 macie. 



Hypophosphites.—The hypophosphites of bis- 

 muth and mercury have recently been carefully 

 examined. They are both obtained by double 

 decomposition of solution of the nitrate of the 

 metal, and of potassium hypophosphite. The bis- 

 muth salts has the composition Bi(H 2 P0 2 ) 3 H 2 

 and is quite stable when dry ; the mercury salt 

 is H g (HP0 2 ), H g N0 3 H 2 ; it explodes when 

 heated to ioo° C—Apotheker-Zeilung. 



