MYCOLOGICAL SECTION. 103 



vessel 15 kilograms of air-slaked lime are mixed in 30 Uterrj of water. When the sul- 

 phate of copper is completely dissolved and the lime forms a homogeneous mixture, 

 the latter is poured into the sulphate of copper solution, the mixture being stirred 

 in the preparation. There is thus obtained a clear Vjlue precipitate, which settles to 

 the l)ottom of the vessel. This precipitate should be stnred up at the time of using, 

 to put it in suspension in the v."ater.'"" 



(2) Audoynaud liwcess. — M. Audoynaud, professor of chemistry in our school, has 

 proposed to sprinkle the leaves with ammoniacal sulphate of cojjper. This liquid is 

 made in the follo^^'ing manner : In a stoneware or glass vessel 2 or 3 liters of warm 

 water are poured upon a kilogram of sulphate of copper, which is stirred with a wooden 

 or glass rod to hasten solution. When cooled, a liter of commercial ammonia is 

 added. This liquid is finally mixed in a suitable cask with sufficient water to make 

 200 liters, whicli serve for the treatment of one hectare. f The application of this 

 liquid is made by means of the Riley sprayer. 



(3) Snlphated sulphin-. — M. Theophile Skawinski, at Chateau Laujac, in Gironde, 

 and M. D. Cavazza, director of the school of viticulture at Alba (Piedmont), have 

 used successfully mixtures of pulverized sulphtir with 8 to 10 per cent, of sulphate 

 of copper finely triturated. 



These three remedies have shown themselves efficacious, but the one which ap- 

 pears thus far to have given the most security from the Mildew is the second. It 

 has the advantage of adhering strongly to the leaves, remaining upon them until 

 their fall. The salts of copper, thus applied to the leaves, act by preventing the ger- 

 mination of the conidia, and consequently the development of the Peronospora. 



By referring to the table showing the results of the experiments of 

 Messrs. Millardet and David, it will he seen that the Audoynaud 

 liquid {Eau celeste) did not give good results in their hands, and, 

 besides, its application injuriously affected the foliage. 



In October last (1886) there was held at Florence, Italy, an inter- 

 national congress for the "exhibition of machines and apparatus for 

 the preparation, transportation, distribution, and application of reme- 

 dies against fungi and insects." At the same time there were held a 

 number of special meetings for the discussion of the fungus diseases 

 of the vine and the remedies to be employed against them. Accord- 

 ing to an official report of these meetings, the conclusions in resjDect 

 to remedies were: (1) That gaseous remedies applied against the Pe- 



*In respect to this remedy Professor Foex, in an article in the June number (1886) 

 of La Vigne Americaine , says: 



"Its action is due to the copper which it contams. The presence of this metal, 

 even in a very minute quantity, in drops of dew or rain on the upper surface of the 

 leaves, prevents the germination of the conidial spores which may have been brought 

 there by the wind. Thus forestalled, the disease cannot establish itself upon the 

 leaves. 



"■Mode of application. — The copper mixture should be distributed by sprinkling in 

 little drops on the upper surface of the leaves. Two or three spots thus produced 

 suffice to completely jjreserve a leaf, and they become sufficiently adherent and co- 

 herent, as soon as they have dried, to remain until the leaves fall. 



"The sprinkhngs were made in Gironde, in 1885, with a simple broom of heath, 

 which was plunged into a bucket or watering-pot containing the mixture. This 

 plan of operating gives satisfaction so far as the distribution of the substance is 

 concerned, but it has the inconvenience of being somewhat slow, and it requires 

 much hand labor; therefore apparatuses have been devised which permit more rapid 

 operation at a less expense of muscle. The one which gave the best results at the 

 trial held in Montpelher, in Febniary, 1886, was that of Mr. Delord, 9 Rue St., 

 Gilles, Nimes. 



" Time when the treatment slioiild he made. — The salts of copper having the effect, 

 as we have seen, of preventing the disease from becoming established, their use 

 should be preventive. The vines should, therefore, be treated before May 15, at 

 which date the Perononpora has sometimes made its appearance in certain places in 

 the Department of Herault. In operating at so early a date only a small portion of 

 the leaves can be reached, the greater number developing between this period and 

 the 1st of June. In practice, therefore, it is better i^robably to sacrifice, if need be, 

 some of the first leaves, and make the treatment only when the vegetation has 

 reached a sufficient development, say, in Herault from the 1st to the 15th of June." 



f One hectare = about 2^ acres. 



