Materials and Formulas. 117 



The 26 Beaume ammonia is the strong ammonia of com- 

 merce, and in the end it is the cheapest form to buy. The 

 liquid loses its strength very rapidly unless it is kept in 

 tightly closed vessels, bottles having glass stoppers being among 

 the best. It must be handled with extreme care, for the fumes 

 are so overpowering that serious consequences may result unless 

 the operator lias at all times fresh air to breathe. Strong 

 ammonia is readily diluted with water to any desired extent. 

 Cost of 22 Beaume seven to twenty cents per pound. 



AMMONIATED COPPER SULPHATE. According to the " United 

 States Pharmacopoeia" of 1870, this substance maybe prepared 

 as follows : " Take of sulphate of copper half a Troy ounce ; car- 

 bonate of ammonium 360 grains. Rub them together in a glass 

 mortar until effervescence ceases. Then wrap the aminoniated 

 copper in bibulous paper, dry it with a gentle heat, and keep it 

 in a well stoppered bottle." The sixteenth edition of the "United 

 States Dispensary," 1877, contains the chemical reactions which 

 take place, and very complete information. When the prepara- 

 tion is exposed to the air it is said to part with the ammonia, 

 resulting in the formation of carbonate of copper and ammonium 

 sulphate. It has been used by the United States Department of 

 Agriculture in a preparation known as mixture No. 5. 



ANALYSES of various substances are here inserted together 

 for sake of convenience of comparison (page 118). The table 

 is taken from the Massachusetts State Agricultural Experi- 

 ment Station, report for 1893, page 378. 



ARSENIC ; ARSENIOUS ACID ; ARSENIOUS ANHYDRIDE ; 

 WHITE ARSENIC ; WHITE OXIDE OF ARSENIC ; ARSENIC TRI- 

 OXIDE ; As 2 O 3 . The element arsenic stands midway between 

 the metals and the non-metals. When pure it is a solid, having 

 a metallic lustre and a steel-gray color. It is but little used, 

 the compound commonly sold as arsenic being arsenic trioxide. 

 This is a white crystalline powder, which is gritty like sand. 

 It is soluble in cold water to the extent of 1 part in 100 ; boiling 

 water, however, dissolves 1 part in about 10 of water. 



A solution of white arsenic has a caustic action upon foliage 

 if a sufficient amount of the poison is present. Danberry 

 records 1 an experiment in which one hundred square feet of 

 young barley was watered with a solution of arsenious acid, 



1 Jour. Chem. Soc. of London, 1862, Vol. xiv. 225. 



