379 



Production of ozone by oxidation of volatile hydrocar- 

 bons. — It has for a loug time been a generally accepted fact that ozone 

 is produced in the absorption of oxygen by essential oils, and in 1863, 

 in a paper read before the Chemical Society of London, Lawes, Gilbert, 

 and Pugh stated their belief " that the ozone said to be observed in the 

 vicinity of vegetation is due rather to the intense action of the oxygen 

 of the air upon minute quantities of volatile hydrocarbons evolved by 

 the plants, than to any action within the cells." These views seem to 

 have been proved fallacious from the results of certain investigations 

 embodied in a paper lately read before the same society by Mr. Charles 

 T. Kinzett. He has experimented with a large number of the volatile 

 hydrocarbons, and finds that the reactions heretofore believed to indi- 

 cate the presence of ozone, are due merely to the presence of easily-re- 

 ducible oxidized j)roducts of the hydrocarbons themselves. His experi- 

 ments have been of a very thorough and exhaustive character, and the 

 conclusions he has arrived at are doubtless correct. Experiments made 

 in the laboratory of this Department, with the oil of Eucalyptus globu- 

 lus, though not as extensive, have furnished results teuding to confirm 

 his conclusions. 



BOTANICAL NOTES. 



By Dr, Geokge Vasey. 



Grasses for the South. — The question of what grasses are best 

 adapted to the wants of the Southern States is one which is receiving- 

 deserved attention at the present time. A correspondent in Brazil has 

 sent us some specimens of three kinds of grasses which are most esteemed 

 for cultivation in that country, and his account of them may have some 

 value with reference to our own country. 



lis'o. 1 is the Eleusine Indica. He says : 



This is the grass with which the pastures are made in this province, geuerally ou 

 bottom lauds, and it is considered that cattle and horses become as strong on this grass 

 as when fed ou corn. The Brazilians call it graminea ; but it is not the r/ra?H?rta of 

 Europe, and I thiuk it is native. It runs ou the ground, and takes root at the joints, 

 and is extremely hard to eradicate ou good ground. It forms a very heavy sod. The 

 Americans say that it is the Bermuda grass, l)ut I think it impossible. It is the most 

 Yaluable grass here. 



In botanical works the common or vulgar name given for this grass is 

 dog's tail, or wire grass. It is much like the Chjnodon dactylon, or Ber- 

 muda" grass, but coarser and heavier. 



No. 2 is a si)ecies of liottboelUa, of which he says : 



No. 2, Gramma roxa. — This, I think, is a species of Rottlndlla, of which we have sev- 

 eral in the United States. It is not many years since it was introduced into Brazil, 

 and it has the advantage of the graminea in that it grows on poorer ground and stands 

 the frost better. It is more hardy in habit. I think it is not a native, although we 

 have native species. A Brazilian told me that he saw this grass in England. The Brazil- 

 lians have cultivated it only a few years, but it promises to be a very valuable grass. 



Although we have several species of this genus in the Southern 

 States, it has not, so lar as we are aware, attracted any attention as a 

 valuable grass. 



No. 3 is a species of Fanicum, of which our correspondent says : 



Caplm de Angola. — This grass, as its name imports, probably comes from Africa, and 

 in rich, moist ground will produce on the same ground probably more vegetable matter 

 than any other grass in the world. It grows in favorable places 30 feet in height, and 



