Intelligerice and Miscellaneous Articles. 4-Of * 



formed by the mixture of solutions of proto-chloride of tin and of 

 iodide of potassium. A more detailed account of the properties of 

 the iodides of tin is reserved for a future communication. !*M:m 



Supplement to a Paper "On the Nervous Ganglia of the Uteruii." 

 By Robert I^e,M.D.,F.R.S., Fellow of the Royal College of PhJ^i 

 sicians. ■'"' 



The author is confirmed in his views regarding the arrangement 

 of the nervous filaments distributed to the uterus, as described in his 

 papers printed in the Philosopliical Transactions for la-il and 1842, 

 by his recent dissection of a gravid uterus at the full period, and 

 which he considers as demonstrative of the accuracy of all the state- 

 ments which are contained in those communications. •' ' 

 , ,. , ,m \ 



LXIII. Intelligence and Miscellaneous Articles. ; ' 



ON THE RED COLOUR OF LITHARGE. BY M. LEBLANC. 



THE author remarks, that M. Fournet is of opinion that red li- 

 tharge contains more oxygen than yellow litharge, and that it 

 owes its colour to a certain proportion of minium ; and several spe- 

 cimens yielded him unquestionable traces of it. M. Thenard and 

 most other chemists attribute the colour of litharge to the same 

 cause, 



The author, without denying that litharge slowly cooled may in 

 certain circumstances absorb oxygen and give rise to minium, and 

 which is stated to be a fact, is of opinion that another cause must be 

 assigned for the production of red litharge ; and his grounds for this 

 opinion are the following : — 1st, the red litharge which he examined 

 yielded no oxygen by heat ; 2nd, the same litliarge, carefully exa- 

 mined by means of pure nitric acid, gave no binoxide of lead, whereas 

 a trace of minium, added to yellow litharge, without even modifying 

 its tint, was discoverable by this test ; 3rd, red litharge, heated to a 

 temperature at which it disengaged no oxygen, and quickly thrown 

 into water, became yellow. Experience shows that these variations 

 of structure and colour in litharge, dependent upon the temperature 

 at which it is produced, are not occasioned by changes of chemical 

 composition, but by isomeric or dimorphous modifications ; the difi- 

 ferences are also connected with the different densities of the speci- 

 mens. 



The author concludes from his experiments, that oxygen may bs 

 dissolved by litharge in fusion, as it dissolves in silver, without form- 

 ing a superoxidized compound ; he is further of opinion that the dift.?' 

 ferences between specimens of litharge are those of structure, colour, 

 and density, without any variation in chemical composition ; and 

 these differences are produceable at pleasure in the dry way, accord- 

 ing to the circumstances of temperature and rapidity of cooling.—- 

 Journ. de Pharm. ei de Ch., Septembre 1845. 



ANALYSIS OF THE SILICATE OF MANGANESE FROM ALGIERS. 

 BY M. EBELMEN. 

 This mineral is found in veins in the primary formation of th? en- 

 Phil. Mag. S. 3. Vol. 27. No. 181. Nov. 184-5. 2 11 



