442 



has beeu but little discussed. At a late meeting of the Eoyal ETorticultu- 

 lal Society at Birmiugham, England, a paper was read by Charles 

 Eoberts, F. K. 0. S., introducing the discussion of sulphur and its mode 

 of action on the lower forms of life, iu a manner which promises to 

 throw much light on an occult subject. Mr. Eoberts' chief argument 

 is directed to the proof of the proposition that the effects are not pro- 

 duced by sulphur, as such, but by its lowest combination with oxy- 

 gen — sulphurous acid, or, as he names its gaseous form, sulphozone. 

 Pure sulphur is insoluble iu water, and therefore cannot act chemically on 

 organisms, whether animal or vegetal)le5 and there is nothing in its phy- 

 sical form that would enable it to act mechanically in a manner injurious 

 to life. This conclusion was reached from careful and often-repeated 

 series of experiments by which it was demonstrated that sulphur, tho- 

 roughly purified from all traces of sulphurous acid by repeated wash- 

 ings, is utterly ineffectual in destroying mildew or other organisms, 

 and that seeds germinate as readily in such sulphur as in sand. Pure 

 washed sulphur, mixed with a little flour and moistened with water, 

 covers its surface with mokl in a few days, if kept at a favorable tem- 

 perature^ and cheese mites live and multiply indefinitely in cheese 

 covered with pure sulphur. These results were all reversed when the 

 common flowers of sulphur were used. This always contains an appre- 

 ciable amount of sulphurous acid. Prosecuting this line of experiment, 

 it appears that the efflciency of sulphur, in any form in which it is used 

 to destroy or prevent fungoid or i)arasitijB growths, depends entirely on 

 the quantity of sulphurous acid present. Charcoal, and many other 

 substances capable of absorbing and retaining gaseous sulphurous acid, 

 is, when thus impregnated, as eflectual as sulphur in destroying mih 

 dew and kindred organisms. 



In the light of these facts, Mr. Eoberts adds : "From my experiments 

 and observations, and from the well-known i)roperties of sulphurous 

 acid, I conclude, therefore, that it is the acid, accidentally present in the 

 suliDhur, whiclii^the active agent in the destruction of mildews and 

 blights, and that the sulphur is only the medium for its application." 

 The acid may be dissolved in water, as well as absorbed by porous 

 bodies other than sulphur, and thus furnish a very convenient form for 

 its use in the destruction of parasitic growths. For horticultural pur- 

 poses, however, a i)recaution will be necessary in using solutions of sul- 

 ])hurous acid, to limit the strength of the solution, lest in destroying 

 parasites the remedy may prove destructive to the plants also. As 

 some plants will endure a much more concentrated solution than others, 

 the proper strength adapted to any given case must be left to the judg- 

 ment of the gardener. 



In addition to its power over vital forms and forces, sulphurous acid 

 exerts a notable chemical action on dead animal and vegetable matter, 

 iSuspendiug, to some extent, the usual process of decay and dissolution, 

 and destroying or modifying emanations from jiersons suffering under 

 infectious diseases. It is, therefore, a most potent and valuable disin- 

 fectant. How sulphurous acid operates to produce its effects both on 

 the life and form of organisms is a question that opens a field to the 

 physiological chemist which has beeu but little explored. 



Welding copper. — The Journal of the Franklin Institute says that Mr. 

 Eust has succeeded in perfecting a method by which he accomplishes a 

 most perfect welding of copper. He mixes together 358 parts of phos- 

 phate of soda and 124 parts of boracic acid. This powder is applied 

 v.hen the metal is at a low red heat; it is then brought to a cherry-red 

 and at once hammered. A wooden hammer is recommended. 



