300 



NATURAL-PHILOSOPHICAL COLLECTIONS. 



On the Chemical Compositioti of Cheese. By M. R. Bhandes.— It results 

 from M. Brandes' researches on the chemical composition of cheese, made in the 

 fkrm-houses, that in 4 oz. there are as follows : — 



'1. A gelatinous animal substance, or caseous matter somewhat mo- 

 dified by aposepedine (caseous oxide,) common salt, and phos- 

 phate of lime^ ------ 10 graint. 



2. Aposepedine, - - - - - - 65 



3. Aposepedine combined with ammonia ; an animal matter soluble 



in water and precipitable by the tincture of galls ; acetate of am- 

 monia ; muriate of soda, and traces of phosphate and sulphate 

 of soda, - - - - - - - 379 



4. Sebacic acid and sebate of ammonia, - - - - 165 



5. Sebacic acid and oleic acid combined in part with ammonia, - 15 



6. Aposepedine with ammonia and a gelatinous animal matter, - 30 



7. More or less altered caseous matter, with sebate of lime, aod 



traces of phosphate of lime, ----- 165 



The other parts contained in the cheese consist of water and seasoning, such as 

 cunjmin-seed. 



The principal mass of a well prepared cheese, then, consists of aposepedine 

 combined with ammonia, of free aposepedine, of sebacic acid and sebate of am- 

 monia, of a gelatinous animal matter, and of caseous matter more or less modi- 

 fied. In the caseous fermentation tliere is formed, besides aposepedine and the 

 sebacic and oleic acids, a great quantity of ammonia, which combines with those 

 acids, but which is partly dissipated when the mass is dried or heated. It is al- 

 most beyond doubt that aposepedine is formed at the expense of caseous matter ; 

 but we have less clear notions of the formation of sebacic acid, whose proportion 

 is very great. M. Brandes remarks, that the composition of decayed and poison- 

 ous cheese has no appreciable diiference from that of whoksome cheese ; that se- 

 bacic acid cannot be considered as the poisonous principle, and that it consequently 

 remains a subject for investigation to ascertain the difference between the two.— 

 Archiv. der Apotheken-Vereins. xxix. 71. 



Extract from a Letter of Professor Harding to Dr. Tiarks, dated Gottingen, 

 December 19, 1829. Read before the Astronom. Soc. — " I observed the observa- 

 tion of Aldebaran on the 9th December, and the sky being perfectly clear, I obtain- 

 ed the moments of immersion and emersion with extreme precision. The first creep- 

 ing out of the star at the emersion was easily perceived, by the contrast of its red 

 light with the white light of the moon's limb ; and I think that the observation 

 of the emersion is as accurate as that of the immersion. I devoted all my atten- 

 tion to the observation, with a view to the well-known phenomenon of the star's 

 remaining visible some seconds on the moon's disc, which has been repeatedly ob- 

 served in this star, and whicli I liave myself seen several times. I remained at 

 the immersion, as well as at the emersion, 10 seconds before the telescope without 

 turning my eye off, but nothing of the kind was seen." — Ann. of Phil. June 1830. 



Supposed New Vegeto-Alkali — Chinio'idia. — MM. Henry, jun. and Delondre 

 have made numerous experiments to determine whether such an alkali really 

 exists as that which Serturner has named Chinio'idia, and they have arrived at the 

 following conclusions : — 



1st. That there remains little doubt as to the non-existence of chinoidia, and 

 that it appears demonstrated that it is only a modification of quina and cinchonia 



