262 STATE IIORTICULTUKAL SOCIETY. 



well ; but the alternative to liave frnit heavily sugared, or not to have it at all, 

 is an alternative that it were well to be relieved IVom. 



The antiseptics, for the most part, exert little change upon fruit constituents, 

 and no serious objection lies against their use on this ground. 



Fruit constituents are frail and delicate compounds. Nature has presented 

 them in harmonious and favorable proportions. Xone of the methods of pres- 

 ervation above considered leaves the integrity of the constituents, and the pro- 

 portion of their quantities fully unimpaired. Nevertheless, some of these 

 methods of preservation, when well executed, furnish valuable foods, slightly 

 modified from fruits, but well worthy of a high place among nourishing and 

 grateful articles of diet. 



There yet remains to consider, regarding the so-called canned fruits, the 

 liability of injurious contamination by the material of the vessel. It is only 

 the (iniied articles which suffer this liability. The acids of fruits have a degree 

 of solvent power upon tin, Wlierever the sheet-iron basis is exposed, the tin 

 is more rapidly dissolved, and some iron is also dissolved. Several chemists 

 have made series of analyses of tinned canned goods, and the reports substan- 

 tially agree that the majority of the cans contain some dissolved tin, 

 and a small proportion of the cans contain enough dissolved tin to affect 

 the taste and to be a matter of inquiry regarding the influence upon the human 

 system. There is no reason to regard tin as a cumulative poison, like lead, 

 and there is nothing known as to the efi'ect of taking continued minute por- 

 tions. In large quantities, dissolved tin is an acute poison. There is little 

 doubt, however, but that dissolved tin is an unwholesome, as well as a disagree- 

 able addition to human food. If tin must continue to be used, the best of tin- 

 ware should be employed, and the goods should not be kept for years, but pro- 

 vided for early use.* Lead has not been found, though searched for, in 

 canned goods. 



DISEASES OF TREES AND SHRUBS OCCASIONED BY VEGETABLE 



PARASITES. 



V. M. SPALDING. 



In attempting to give an account of those diseases of trees and shrubs that 

 are traceable to the influence of vegetable parasites it is hardly necessary to 

 state that we are dealing with a subject that in some of its aspects at least is 

 still imperfectly understood. It is this very fact however that ensures the con- 

 tinued investigation of the diseases, and it is hardly to be regretted that some 

 such cause still remains to compel attention to the most insidious and i)ersist- 

 ent enemies of the cultivator of trees and fruits. It will prepare the way for 

 our study of the subject to glance first at a few of the most prominent charac- 

 teristics of the fungi, the great division of plants to which most of these par- 

 asites belong. 



Fungi include all those peculiar organisms popularly known as mould, mil- 

 dew, rust, smut, bliglit, and the more conspicuous, but to the fruit-grower 

 much less important, I'orms, called mushrooms, toadstools, and puft-balls. They 

 are all of vegetable origin and therefoi-e proper sulijects of botanical study and 



* See report of G. L. Pnhiicr, in contributions from clicniiciil laboratory of the University of 

 JlichiRan, p. 23. Also, nn article liy A.I$. I'rescotl, Sanitary Kngincer, 1882, fnov ItJ, p. 515. Further, 

 a Bumniary by Otto Ilulincr, the Analyst, London, vol. 0, p. 218. 



