OF ARTS AND SCIENCES. 85 



VI. 



CONTRIBUTION FROM THE LABORATORY OF S. P. SHARPLES. 



* 



SCHWEINFURT GREEX: 



SOME EXPERIMENTS ON THE ACTION OF ARSENIC TRIOX- 

 IDE ON COPPER ACETATE, WITH THE VIEW OF INVESTI- 

 GATING THE COMPOSITION OF THE ABOVE COiVU'OUND. 



By E. R. Hills. 



Read by title, November 8, 1876. 



After the completion of the paper on Scheele's Green by Professor 

 S. P. Sharpies, I became interested to know something about the com- 

 position of the closely allied substance, Schweinfurt green, — as to 

 whether it was perfectly definite in its composition, or whether it varied 

 in a similar manner to Scheele's green. I therefore obtained a sample 

 of Schweinfurt green from the Massachusetts Institute of Tech- 

 nology, which was procured by them in the market for analysis. 

 This was submitted to a careful analysis, and gave as follows : — 



Analysis No. I. 



99. GO 



If now we deduct from this the sulphuric anhydride and barium sul- 

 phate, and calculate the percentages anew, we have, — 



Per cents. Atomic Ratios. 

 Copper oxide, 29.88 4.26 



Arsenic trioxide, 52.30 3.00 



Acetic anhydride, 17.82 1.98 



100. 



