24 VETEEINARY STATE BOARD 



combustion of sulphur or by roasting iron pyrites in a suitable 

 furnace, is passed into a large chamber, or series of chambers, lined 

 with sheet lead. Nitrous fumes, produced by heating sodium nitrate 

 with a little sulphuric acid, enter the chamber at the same time; 

 jets of steam are blown in at several points and a draft of air is 

 kept up throughout. The sulphur dioxide meeting the nitrous fumes 

 is oxidized by them and with the water of the steam forms sulphuric 

 acid. 



Uses: Very extensively used in the arts, in the manufacture of 

 all the other strong acids, and fertilizers; refining sugar, fats and 

 oils ; in galvanic batteries, etc. 



Write the graphic formula and calculate the percentage composition 

 of sulphuric acid. [Atomic weight of 8 = 32.] 



H-0\g/0 



H-O-/ ^0 



2 + 32 + 64 = 98, the molecular weight of sulphuric acid. 



2/98 or 2.04 per cent, hydrogen. 



32/98 or 32.65 per cent, sulphur. 



64/98 or 65.30 per cent, oxygen. 



What is copper sulphate? How prepared? 



Copper sulphate, Hue vitriol, or blue stone, is the most im- 

 portant compound of copper. It is formed in large, transparent, 

 deep-blue crystals which are easily soluble in water and have a 

 nauseous, metallic taste. Formula, CuSO^. 



It is prepared by dissolving cupric oxide in sulphuric acid, 

 evaporating and crystallizing the solution. 



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DISINFECTANTS AND ANTISEPTICS 



Differentiate between disinfectants and antiseptics. 



Disinfectants are agents that destroy the microorganisms which 

 cause infectious and contagious diseases, fermentation and putre- 

 faction. 



Antiseptics are agents which prevent the growth and develop- 

 ment of the microorganisms occasioning fermentation but more 

 especially the pus-producing variety. 



What is a deodorant? 



Deodorants are agents which destroy or counteract a foul odor, 

 e.g., phenol, zinc chloride and charcoal. 



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