380 Miscellaneous Intelligence. 



of oxides containing tartaric acid could not be precipitated by alka- 

 lies or their carbonates, though they fell immediately if that acid were 

 away. Among these is the oxide of titanium, which is not then 

 precipitated by the alkalies or carbonates; also alumine, of which the 

 presence cannot be discovered in a solution containing tartaric acid ; 

 oxide of manganese, oxide of cerium, yttria, oxide of cobalt, oxide of 

 nickel, magnesia, protoxide of iron, oxide of lead, when the solution 

 contains nitric acid to keep the tartrate from precipitating, oxide of 

 copper, and finally oxide of antimony, of which the solutions con- 

 taining tartaric acid are not prccepitated, either by alkalies or any 

 abundance of water. 1 have employed this property of oxide of an- 

 timony with much success, in the analysis of the salts and ores of that 

 metal, Though oxide of bismuth docs not possess this property, it 

 does not afford a means of separating it exactly from oxide of anti- 

 mony. There is scarcely any acid but the tartaric which possesses 

 this remarkable property of forming salts with many oxides, which 

 cannot be precipitated by the alkalies. The phosphoric and arsenic 

 acids arc the only ones which in this respect, present any analogy.— 

 Ann. de Chim. xxiii. 356. 



12. On two Nac Coloured Test Papers. — The following account of 

 these test papers is abridged from the description given of them by 

 M. C. Pagot des Charmcs, who has used them for many years with 

 advantage in testing for acids and alkalies. 



The first is obtained from the violet pellicle, which covers the root 

 of the small radish, (raphanus sativus oblongus,j the second from the 

 skin of the common red radish (raphanus vulgaris.) The directions 

 with respect to the small radish, are to scrape off the coloured skin with 

 a knife, and as it soon changes in the air, to collect them rapidly, 

 put them in a piece of clean linen, and compress them, when a clear 

 transparent blue fluid will be obtained. This test fluid may be pre- 

 served as it is out of the contact of air, or made into a syrup, or laid 

 on paper by a brush ; and the paper thus prepared, preserves its fine 

 sky-blue colour in contact with the air for any length of time. This 

 test is extremely sensible to acids and alkalies. 



The scrapings of the common radish require to be bruised in a 

 mortar before pressure ; they do not yield so much juice, but the 

 tint is very fine either in the fluid state, or on paper, and the test it 

 affords is a very delicate one. These preparations are recommended 

 above litmus, by their being equally sensible, and yet unaltered 

 in the air, and by being readily obtained every where. — Jour, des 

 P/iys. xcvi. 136. 



13. On the Presence of Ammonia in Rust of Iron, formed in habited 

 Houses, — M. Vauquelin was called upon to examine some red spots 

 found on a sabie, which was supposed to have been used in the com- 

 mission of a murder, the spots being produced by blood ; a small 



