1S13.] 



Scientific Intelligence, 



65 



brought to a boiling temperature, in a copper vessel well linned. 

 The starch is to be mixed with the other half of the water. It is 

 then passed through a seirce, and gradually mixed with the boil- 

 ing acid liquor, in quantities amounting to about half a part at a 

 time. The whole is kept boiling for 36 hours, water being added 

 to supply the place of what evaporates. Then some powdered 

 charcoal is added, and last of all a quantity of chalk, sufficient to 

 saturate the sulphuric acid. After a little additional boiling the 

 liquid is passed through a cloth, to separate the selenite. It is 

 then evaporated by a very gentle heat, to the consistence of a 

 syrup, and set aside for chrystaliization. The liquid, when it 

 passes through the cloth, ought to be as transparent and colour- 

 less as water. The christallization usually take^ place in about 

 three days after the evaporation, No cori cct details respecting 

 the nature of this sugar have been hitherto published; but it 

 appears to approach nearer to the sugar of grapes than to that 

 which is obtained from the sugar cane. 



Attempts have been made to convert wheat flour into sugar 

 by a similar process ; but they have not succeeded. The pro- 

 portion of sulphuric acid may be augmented ; but in that case a 

 greater proportion of water must be employed, and the period ef 

 boiling must be lengthened; so that in reality nothing is gained 

 by this addition. 



This curious process promises to throw additional light on the 

 constitution of vegetable substances. In point of economy very 

 little is gained, starch is in reality dearer tlian common sugar. 

 Hence, even supposing starch-sugar possessed the requisite qua- 

 lities, it never could come in competition with common sugarj 

 far less supplant it. At present it would be a much more valua- 

 ble discovery in this country, to convert sugar into starchy than 

 starch into sugar. 



III. Artificial Grasses. 



Almost the only grass sown in Great Britain is the rye-grass 

 {LoUium peremie). This preference is not v/ithout reason. It 

 yields the most abundant crop of hay of any of the grasses; and 

 it appears from various trials that have been made, that rye-grass 

 hay is more nourishing than that made from any other species of 

 grass. Another advantage is its earliness, and its leaves are not 

 so coarse as to render it necessary to cut down the grass before it 

 IS ripe ; so that both hay and seed may be procured from the 

 same field. The after crop of grass \s likewise luxuriant, 



The dlopeciirus pratensis, ov foxtail or ass ^ lias been highly ex-° 

 tolled by some farmers, and probably it answers very well for 

 grazing ; but it is greatly inferior to rye-grass for the purposes of 

 hay. The j^orm g?ms of Dr. Richardson, which has been con- 

 sidered by every person as the agrostis stolomfera^ though iii , 



Vol, L N° I. E 



