Scientific Intelligence. 26 



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SCIENTIFIC INTELLIGENCE. 



L Chemistry and Physics. 



1. On Margaritinic Acid; by Louis Saalmueller, (communicated 

 for this Journal, by M. Schleiper.) — During my stay in Giessen, I oc- 

 cupied myself vviih the investigation of castor oil, but from want of 

 time, and material, I was prevented from studying more closely the 

 solid fat acid of this oil. Since that time I have had occasion to pro- 

 cure larger quantities of the sediment deposited from castor oil, which 

 has enabled me to investigate more exactly the qualities of the mar- 

 garitinic acid. In spite of the great difficulties which offered them- 

 selves, in the way of obtaining this acid of a constant melting point, I 

 think I am enabled to state it pretty accurately. From 5 pounds of 

 the above mentioned precipitate, treated according to the method which 

 I have described in my former paper on this subject, (Annalen der 

 Chemie und Pharmacie, vol. lxiv, p. 108,) I obtained only 10-12 grammes 

 of the solid acid. The melting point of the solid acid, free from alka- 

 lies, was at first 25° C. ; but by more than twenty recrystallizations, 

 I succeeded in getting an acid which melted at 51° C., and which melt 



ing point remained constant, — at least, it did not change any more at 

 the three last crystallizations. 



Bussy and Lecanu called this acid margaritinic acid, from its pearly 

 lustre. It was obtained as mentioned previously, by saponification of 

 the oil, separation of the fat acids by means of monobasic acid, and 

 mixture of the fluid fat acid with J alcohol. By keeping this mix- 

 ture a longer time at a temperature below the freezing point, the sepa- 

 ration of the solid acid commences, but mixed with bicinoleic acid in 



combination with potassa. To purify the crude acid it is necessary to 



Press it repeatedly between blotting paper, and recrystallize it many 

 times from alcohol, adding small quantities of muriatic acid, to separate 

 the strongly adhering potassa. The white mass swimming on the sur- 

 face was then filtered off, washed out, pressed between paper and 



dissolved in strong alcohol ; this solution by means of spontaneous 



a /"«fcm, snining, , 



without leaving any residue. The acid cannot be distilled without de- 

 composition ; the distillate which I obtained, had a melting point of 

 54 ° C, was colored yellow, and in the retort there remained a light 

 spongy coal. 

 The analysis of this acid gave the following numbers :* 



I. 0-3525 grm. acid burnt\vith chromate of lead, gave 10025 grm. 

 carbonic acid and 0-4145 grm. water. 



II. 0-235 grm. acid gave 0-6715 grm. CO* and 0*265 grm. HO. 

 HI. 0-256 " « u 0-7372 zrm. CO~ 2 and 0-2972 grm. HO. 



According to my previous invest Nations, the melting point, just as well as the 

 amount of carbon of the solid acid seems to change, in the different sorts of castor 

 oil, which supposition is more strongly confirmed, by my present investigation. 



