£46 



DR. GREGORY S STRICTURES ON DON RODRIGUEZ. 



Exp. To shew 

 the propor- 

 tions of sul- 

 phur and of 

 oxigen which 

 pa rattly 

 unite with 

 a definite 

 quantity of 

 antimony. 

 White oxide 

 and sulphur 

 were heated 



nnd digested it with the surtartrate of potash : the stibicus 

 oxide was dissolved, while the white oxide was separated in the 

 form of an extremely white and voluminous powder. 



In order to compare the quantity of oxigen in the white 

 oxide with the quantity of sulphur which can combine with 

 the metal it contains, I mixed 100 parts of white oxide with 

 100 parts of sulphur, and heated them together in a small phial 

 exactly weighed, which had a narrow neck, and of which the 

 aperture was closed with a stopper of charcoal. The heat pm- 

 ployed was at first very gentle, until the disengagement of sul- 

 phureous acid had ceased, after which I heated the phial amidst 

 the burning charcoal until theuncombined sulphur was entirely 

 dissipated, and the buton of sulphnret remained infusion at the 

 bottom of the phial. It weighed 107*25 p. Although the 

 volatility of the sulphuret of antimony could not be perfectly 

 obviated in this experiment, I have reason to think, that the 

 length and smallness of the neck of the phial prevented any 

 loss, and more especially as the mass was never so much heated 

 as to put it into a state of ebullition- - . 



(To he continued.) 



Surprise on 

 seeing an at- 

 tack on the 

 English na- 



III. 



A Reply to Don Joseph Rodriguez's Animadversions on Part 

 of the Trigonometrical Survey of England. By Olinthus 

 Gregory, LL. D. of the Royal Military Academy, Wool- 

 wich, 



To IF. Nicholson, Esq. 

 DEAR SIR, 



WHEN I say that I have been greatly surprised to see 

 in the second part of the Philosophical Transactions for 

 1S12, Don Rodriguez's animadversions upon part of the Eng- 



* I never operated upon a suhstance which in general afforded me, 

 results so various as antimony and its oxides. In order to ascertain 

 whether the oxides, which are often obtained with less oxigen than 

 fury ought to contain, have been volatilized with the acid employed 

 for their oxidation, I heated such an oxide with sulphur, and converted 

 it into sulphuret. 100 p. of antimony produced T28-5 of yellow oxide, 

 which by ignition left 125*8 of white oxide, and these produced with 

 sulphur 137-.? of sulphuret. It appears, therefore, that these oxides 

 contain combinations of different degrees of oxidation, which prevent 

 the saturation with oxigt n. 



