HARDWICKE'S SCIENCE-GOSSIP. 



103 



for ages in Chili and Bogota as attacking the potato, 

 and in 1S44 it proved most disastrous on the 

 American continent, which has given rise to the 

 idea that it was introduced here from the New 

 World. 



The cause and nature of the disease have baffled 

 the ingenuity of the philosopher and the farmer. 

 Many remedies have been tried, not only in this 

 country, but on the Continent and in America. It 

 appears that we are not much more acquainted with 

 its nature than we were when it first showed itself. 

 In Germany some of the scientific men have given 

 much time and study to the subject ; one of these. 

 Dr. J. Speir Schneider, has published his experiments 

 and conclusions in the BotaiiiscJie Zeitung, 20th 

 February, 1857. He considered that the Perono- 

 spora attacked the leaves in the first instance, 

 the ripe spores of which are cast off or carried by 

 the rain into the soil when it is loose, and thus 

 brought into contact with the tubers, where they 

 germinate, under favourable circumstances, and 

 finally induce decay. In dry seasons the disease is 

 not so prevalent. 



Other scientific men hold different views on the 

 subject ; they say that the disease is not caused by 

 this fungus, but that it attends and accelerates it. 

 Further researches into the nature of fungi may in 

 time throw additional light upon this important 

 matter. 



The cultivation of the potato in Europe appears 

 not to have attained to any extent till during the 

 last century. It was introduced into Sweden in 

 1720; but, notwithstandingthe exertions of Linnaeus, 

 it did not come into general cultivation till aided by 

 royal edict in 1764;. It reached Switzerland in 1730, 

 and met with more favour ; the inhabitants in a few 

 years growing not only sufiicient potatoes for their 

 common consumption, but drying and grinding them 

 into flour for bread. Its cultivation in Prussia 

 began about 1738, and in Tuscany in 1767. In 

 France its progress was very slow, and it was not 

 until the middle of the last century that Parmentier 

 urged its cultivation with so much success, that it 

 was contemplated to give his name to the plant, and 

 in 1793 the great scarcity of food did still more to 

 extend its cultivation. The potato has been intro- 

 duced into India. Bishop Heber, in his interesting 

 journal, mentions several places, even in his time, 

 where this root was successfully grown. At first 

 this vegetable was very unpopular among the natives, 

 but now they speak of it as being one of the best 

 gifts they have ever received from their European 

 masters. The Mussulmans in particular hold it in 

 much esteem : they find it very useful as an absorbent 

 in their greasy messes. 



Humboldt states that the cultivation of the potato 

 in the Andes extends to an elevation of 9,800 to 

 13,000 feet, higher than wheat. In the North of 

 Europe it reaches beyond the limits of barley, and 



consequently all cereals : an early kind has been in- 

 troduced into Ireland, where barley will not grow. 

 In tropical regions, according to Johnstone's Physi- 

 cal Atlas, an elevation of 4,000 feet appears to be 

 necessary for the growth of this root. It is suc- 

 cessfully cultivated in Australia and New Zealand, 

 which produces no excellent farinaceous root at all, 

 not even the yam. 



The 1 itato contains large quantities of water,— 75 

 per cent., and less flesh-forming properties than any 

 other plant cultivated for human nourishment, and 

 therefore ought never to form the staple article of 

 diet ; still there is no doubt that the use of this root 

 is highly beneficial when taken with animal food. 

 It is certain that scurvy, which was formerly com- 

 mon, has almost disappeared since the potato 

 entered largely into the food of the population. Dr. 

 Baly, the physician to the Millbank Penitentiary 

 showed some time ago that scurvy was very pre! 

 valent in prisons from the dietaries of which 

 potatoes were excluded, and did not exist where 

 they were used. (See Journal of the Statistical 

 Society, vol. x.) 



Besides its value as a culinary vegetable, the potato 

 is important in other respects. It contains a large 

 proportion of starch, which is easily extracted, and 

 there are extensive manufactories in this country 

 and on the Continent for preparing this article. This 

 starch has a beautiful white crystalline appearance. 

 It is insoluble in cold, but soluble in boiling water. 

 It is often sold for arrowroot, but can readily be 

 detected ; for arrowroot is not so white, and its grains 

 are smaller; it is also free from that peculiar odour 

 due to potato-starch. But it is said to be quite as 

 wholesome and well adapted for invalids and persons 

 of delicate constitutions as arrowroot. From this 

 starch a substance is obtained, called dextrine, re- 

 sembling gum in its appearance and properties. It is 

 largely used in the arts for various purposes : the 

 adhesive portion of our postage-stamps is composed 

 of this substance. A size made from potatoes has 

 a great advantage over common size for the purpose 

 of whitewashing, as it does not smell, and it has a 

 more durable whiteness. Yeast may also be made 

 from these roots fit for the use of either the baker 

 or brewer. In Russia a syrup or treacle, called 

 potato-sugar, is extracted from the tubers, which is 

 extensively used : it is very sweet, and resembles the 

 sugar of grapes, but cannot be crystallized. 



In France a spirit not unlike brandy is manufac- 

 tured by distillation from the tubers, and a kind of 

 oil is also obtained, which burns without smoke, but 

 requires to be heated in order to continue burning. 

 It has also been stated that the potato will clean 

 linen as well as soap. A notice of thirty-one dif- 

 ferent uses to which this root can be applied will be 

 found in the first volume of the Gardener's Maga - 

 zine, page 436. The flour, or farina, of this plant 

 is much used by the baker in bread-making, and 



