— 45 — 



Our sale of artifical oil has increased to a considerable extent. 

 In that line we can meet all competition. 



In one of our last Reports 1 ) we referred to a work on the quantit- 

 ative estimation of mustard oil, by R. Fir b as, in which it was inter 

 alia pointed out, that if the method of estimation indicated in the 

 German Pharmacopoeia is exactly followed, the results obtained are 

 too low, as the decomposition of the thiosinamine silver compound in 

 the cold is not completely finished in 24 hours. By heating it, the 

 values are raised in proportion to the period of the heating. Firbas 

 obtained the highest results when heating in a pressure flask up to 

 about ioo°, but he leaves it an open question whether in this case 

 the contaminations of the mustard oil, which are sparingly soluble, 

 are not included in the estimation. We received the original work 2 ) 

 only at a late date, and now return to this subject, in order to re- 

 produce a table in which Firbas has summarised the results obtained 

 by him, and which will no doubt prove interesting to a larger circle 

 of readers: — 





k> 





• d >>rd 

 3 rt pQ u 



3 ft 



' ho 



3 3 



^ >> bo <u 





08 



O 2 rt 



©"§ " 

 •B p*tj 



~~ 



^ a 5 P 



to the Co 

 the Gerir 

 »oeia IV 

 dHartw 



d 



•5 w b/D 



« '»-• P 



O ■£ 



*" d 

 O J 



;oK.Die 

 hod (Ana 

 on of wei 

 er sulphid 





ho 3 



S>B-i 



^o w § 



bJO'rt <L> 



bo £ 



ho© "S £ 





.3 rt 



.3*8 



^&§* 



.5 p^-P 





.3 a J -a 





u d 



u CLi 



u d S 



O d cj £ 



u d 



w d 



ph j-i "is 





d 



O Rj -M 



w ©.d.2 



U <U 



u 



43 <+-, 





< 6 



< 3^ 



<l BPMfe 



<1 3 



<! 3 



^t-8"° 



Natural oil I . . . . 



84,0 



84,2 



95» 6 



96,0 



96,8 



98,9 



do. I . 









83,6 



83,9 



94, 2 



— 



— 



— 



do. II . 









81,4 



82,1 



94,7 



94,9 



96,1 



97,4 



do. Ill . 









80,2 



80,2 



89,7 



91,6 



91,8 



— 



do. IV . 









84,7 



— 



91,2 



92,4 



— 



95,3 



Artificial oil I 









76,2 



— 



89,4 



9i,4 



91,6 



92,6 



do. II 









84,9 



85,4 



96,8 



97,3 



97,3 



— 



We have in recent times repeatedly had to make estimations of 

 mustard oil of our own distillates, and have found Firbas' obser- 

 vations fully confirmed. The mustard oil determinations carried out 

 exactly in accordance with the instructions of the German Pharma- 

 copoeia without heating, give in every case results which were about 

 8°/ too low, and according to these no mustard oil would satisfy 

 the requirements of the Pharmacopoeia. For this reason it is at the 

 very least necessary to follow the directions given in Fischer-Hart- 

 wich's Commentary to the Pharmacopoeia, and heat the flask for a 



*) Report April 1904, 63. 



2 ) Zeitschr. d. allgem. osterr. Apoth. Ver. 58 (1904) 222. 



