MISCELLANY. 



123 



form, and probably not in origin. There 

 are many Yosernites. Many of the great 

 glacial valleys become deep, narrow canons, 

 with precipitous walls near the junction of 

 the granites with the slates. This is the 

 position of Yosemite. It occurs in the val- 

 ley of the American River and the valley 

 of Hetch Hetchy, which, says the author, 

 almost rivals the Yosemite in grandeur, 

 and, in his opinion, all these deep, perpen- 

 dicular slots have been sawed out by the 

 action of glaciers, the verticality of the 

 walls having been determined by the per- 

 pendicular cleavage of the rocks. 



Origin of the Potato-Disease. — Messrs. 

 T. & E. Brice, of Plymtree, England, claim 

 to have discovered the cause of the potato 

 and the foot and mouth diseases, which they 

 assert to be nothing else but the employ- 

 ment of chemical manures. It is remark- 

 able, say they, that both of these diseases 

 made their appearance about the same pe- 

 riod. It is some 250 years since the potato 

 was introduced into Britain, and there is 

 no record that the disease ever existed 

 until the year 1845, when, subsequently to 

 a continued rain for some days together, 

 the potato was found to be diseased gen- 

 erally throughout the kingdom. Previous 

 to that time the chemical manures had 

 been introduced, and they were used in 

 great abundance the same season that the 

 potato - disease first -appeared. Messrs. 

 Brice were then of opinion that the manure 

 was the cause, and, having since investi- 

 gated its principles and action, they find 

 that it contains a very active poison — sul- 

 phuric acid : " Its particles readily attract 

 the particles of water, producing fermenta- 

 tion, and sometimes causing putrefaction 

 of the compound they adhere to. If the 

 chemical manures are distributed over the 

 land in a dry season, and there is not 

 enough rain to cause fermentation, the sul- 

 phuric acid remains fixed on the earth ; if 

 it is applied in a wet season, the rain causes 

 fermentation ; the effluvium ascends in the 

 atmosphere, and, mixing with the vapors, 

 helps to constitute clouds, when there is a 

 return in poisoned rain and dew on the po- 

 tatoes, and other bodies as well. Putre- 

 faction of the potato is the consequence, 

 and it has a very offensive smell." The 



authors have made some experiments with 

 a mixture of water and sulphuric acid. 

 Fermentation and poisoning of the water 

 were the result, and an application of the 

 mixture to the potato caused disease. 



But the question naturally arises, Why 

 should the sulphuric acid cause disease 

 only in the potato and not in other 

 plants ? and on this point the Messrs. 

 Brice leave us in the dark. Here we 

 may mention another theory which has 

 been proposed to account for this potato- 

 blight. It has been observed that the 

 electrical state of the atmosphere has 

 something to do with the matter, and in 

 Ireland the potato-crop is described as 

 wearing a blighted appearance after a pro- 

 tracted thunder-storm. The theory is, that 

 the electrical condition of the atmosphere 

 causes the conversion of the starch into 

 dextrine, sugar, etc., and the tuber then 

 melts away. But again we ask, Why did 

 not the same causes produce the same ef- 

 fects previous to 1845 ? 



As regards the foot and mouth disease, 

 the cattle and other animals travel and 

 browse where the poison has fallen, and it 

 is taken in with their food. The active 

 particles adhere to their feet, lips, and 

 mouth, destroying the scarf-skin and mu- 

 cous membrane of the mouth and throat. 

 The symptoms are such as might be pro- 

 duced by sulphuric and other corrosive 

 acids. 



A Substitute for Parchment. — Parch- 

 ment-paper has several properties in com- 

 mon with animal membrane. It is obtained 

 by the action of sulphuric acid or chloride- 

 of-zinc solution on unsized paper. When 

 sulphuric acid is employed, the best solu- 

 tion is one kilogramme (2.20485 pounds) 

 English concentrated sulphuric acid to 125 

 grammes (about 4.4 ounces) of water. The 

 paper is dipped into the acid so as to 

 moisten both sides uniformly. The length 

 of time it is to remain in the bath depends 

 on its own thickness and density. The 

 minimum time for the ordinary unsized pa- 

 per of commerce is 5 seconds, the maximum 

 20. When the acid has acted a sufficient 

 length of time, the paper is first dipped in 

 cold water, then in dilute ammonia, again 

 in water, to remove the acid, and finally it 



