(14) Page 62. Iceland or Calc Spar.—Native carbonate of lime in its primitive crystalline form.
LECTURE III.
(15) Page 79. Solution of a Salt.—Acetate of soda. A solution saturated, or nearly so, at the boiling point, is necessary, and it must be allowed to cool, and remain at rest until the experiment is made.
(16) Page 86. Cinoxide of Nitrogen and Hypo-nitrous Acid.—Binoxide of nitrogen is formed when nitric acid and a little water are added to some copper turnings. It produces deep red fumes as soon as it comes in contact with the air, by combining with the oxygen of the latter to form hypo-nitrous acid. Binoxide of nitrogen is composed of two parts oxygen and one part of nitrogen; hypo-nitrous acid is composed of one part of nitrogen and three parts of oxygen.
LECTURE IV.
(17) Page 106. Chlorate of Potash and Sulphuret of Antimony.—Great care must be taken in mixing these substances, as the mixture is dangerously explosive. They must be powdered separately, and mixed together with a feather on a sheet of paper, or by passing them several times through a small sieve.
(18) Page 107. The mixture of chlorate of potash and sugar does not require the same precautions. They may
