480 SEC. 13. CHEMISTRY. 



24191. Specimens of Native Antimony. 



George Gore, F.R.8. 



2421. Pseudo-crystal of Native Ceylon Graphite. Bar of 



extremely pure metallic Tellurium, weighing 2,000 grains. 



George Gore,F.R.S. 



2423. Mercury Distilling Apparatus, constructed according 

 to Dr. A. Weinhold's system. 



T. Bosscha, Professor, Royal Polytechnic School, Delft. 



(Carl's Repertorium der Physik, vol. ix., p. 69), with slight modifications 

 of the mercury reservoirs, giving per hour about 500 grammes of distilled 

 mercury, constructed by M. M. P. T. Kipp and Sons, Delft. 



2425. The Original Air Battery. 



J. H. Gladstone and Alfred Tribe. 



When a plate of copper is connected with metallic silver, and immersed in 

 a solution of copper nitrate, the .oxygen of the air dissolved in the liquid takes 

 part in the re-action, the copper is eaten away, and cuprous oxide is deposited 

 upon the silver. This gives rise to the ordinary voltaic phenomena. 



2426. The Original Copper-Zinc Couple. A.D. 1871. 



J. H. Gladstone and Alfred Tribe. 



This consists of coils of sheet-zinc on which copper has been deposited in 

 a finely divided condition, by pouring copper sulphate upon them, and washing 

 away the salt produced. In this case the coils are separated by layers of 

 muslin. The couple having been immersed in water, has decomposed it, and 

 the zinc is now thoroughly oxidized. 



2427. The Original Copper-zinc Couple of the present 

 arrangement. J. H. Gladstone and Alfred Tribe. 



In this case the zinc foil is crumpled, and covered with the deposited 

 copper. The zinc is now completely covered with oxide through the decom- 

 position of water. 



2428. Tubes showing that the hydrogen prepared from water 

 by the copper-zinc couple does not contain arsenic, though the 

 zinc is so greatly contaminated with arsenic as to give much 

 arseniuretted hydrogen when dissolved in acid. 



J. H. Gladstone and Alfred Tribe. 



2429. Original Specimens of Ethylo-bromide of Zinc, 

 and Ethylo-chloride of Zinc, substances prepared by means 

 of the copper-zinc couple. J. PL Gladstone and Alfred, Tribe. 



2430. Essential Oils and their derivatives. J. H. Gladstone. 



1. Menthene. An oil of the C 10 H 16 group. 



2. Cedrene. An oil of the C 15 H 24 group. 



3. Hydrosulphate of menthole. 



4. Hydrate of oil of turpentine. C 10 H 1G , 3H 2 0. 



5. The same recrystallized from water. 



6. Coeruleine, a deep blue colouring matter found in the essential oils of 

 Matricaria Chamomilla, Artemisia Absinthium, and several others of the C 15 

 H 24 group. 



