520 CHEMISTRY. 



is believed, the Spanish Chesnut gro-ws twice as fast as the oak, then the age of 

 this monument of ancient times must be 575 years. In another place, far away in 

 the park, is a still vigorous gigantic tree, 19 feet in circumference, to -which thd 

 age of 375 years would have to be assigned. 



Novr what we want to know, and what we submit to the consideration of our 

 readers, is how far our calculations are supported by reliable facts. Is it true 

 that the oak grows at the rate assumed ? Is it true that Spanish Chesnuts grow 

 twice as fast? If not, what is their real rate of growth ? and upon what evidence 

 is that their supposed real rate founded ? This seems a subject deserving the con- 

 sideration of some of our experienced foresters." 



MILDEW. 



" We understand that there is great probability of an effectual remedy for mil- 

 dew and red spider having been discovered, wholly free from the objections 

 attaching to sulphur either in powder or in a volatile state. How valuable that 

 agent is we all know ; but it is troublesome to apply, uncertain in its action, and, 

 if mismanaged, more mischievous than the evils it counteracts. As for example 

 when it i§ fired, the effect of which is to charge the atmosphere with fumes of sul- 

 phurous acid, one of the most fatal to vegetation of all known substances. 



At present our information amounts only to this : that Mr. Wilson, the very 

 able and scientific manager of Price's Candle Company, has prepared a soap, 

 which, being dissolved in water and applied with a syringe, does effectually and 

 without the least risk all that flowers of sulphur can do. It is said that one of 

 the principal nurserymen near London has been trying the soapy water, of different 

 strengths, and is very favorably impressed with its efficacy. Six ounces of the 

 soap in a gallon of water killed mildew for the time and continued to keep it down 

 when applied weekly. Pot Roses, after three applications, became nearly clean, 

 and were in fact saved ; their soft young points indeed were killed, but that was 

 of no importance ; the rust of Moss-roses disappeared before its action. In other 

 hands red spider was effectually kept down ; one lb. of the soap dissolved in four 

 gallons of water, completely cleaned even Peach trees after two or three applica- 

 tions, the trees having been well syringed a day cr two afterwards. 



The name of this new soap or substance is, we are informed, " The Gerhurst 

 Compound," and if it is found in other hands to preserve the good qualities 

 ascribed to it, Mr. Wilson will certainly have conferred one of the greatest 

 possible benefits upon horticulture. A trial is about to be made of.it in the 

 garden of the Horticultural Society, at Bowood, Trentham, Chiswicb House, and 

 several other large establishments." 



CHEMISTRY. 



Synthesis of the Hydrocarhons. — The ingenious Berthelot, has published in 

 extenso his experiments on the preparation of organic compounds from inorganic 

 materials, a process of which, chemists possessed but few examples previous to 

 his discoveries. The hydrocarbons which he has obtained, are marsh gas, ok- 



