310 Extracts from the Journals. [April, 



that we are supplied with an additional argument in favor of the 

 importance of having the subject of ash analysis taken up by a 

 public body, possessed of competent means and facilities for de- 

 ciding between the conflicting authorities, and supplying us with 

 a more secure basis for future calculations. — Jlthenceian, No. 919. 



THE POTATO DISEASE. 



The premature disease which has taken place in the potato 

 crop, has induced the government to appoint a scientific com- 

 mission to inquire into the subject in Ireland. Dr. Kane, Dr. 

 Lyon, Playfair, and Professor Lindley, have investigated the mat- 

 ter, and have come to conclusions at which most persons had long 

 since arrived: — 1. That the cause of the decay has been a cold 

 and wet summer. 2. That to prevent an extension of the decay, 

 the potatoes should be dug up, allowed to dry, and then kept in a 

 dry place. 3. That decayed potatoes may by contact or proxi- 

 mity affect those which are healthy— a fact well known in rela- 

 tion to putrefaction in animal substances. Many tubers, however, 

 which are to all appearance sound, are probably partly affected, 

 and the water in which such tubers were boiled, has been observ- 

 ed to have a strong odor analogous to sulphuretted hydrogen, 

 although the potatoes were wholesome and fit for food. 



As the potato disease has extended throughout Europe, the 

 attention of savans on the continent has been directed to its in- 

 vestigation. 



M. Payen has submitted to the Paris Academy of Sciences, 

 some specimens of diseased potatoes, and read a note on the phe- 

 nomena which his examination of them has presented to him. 

 The change seems to M. Payen to be transmitted from the stalks 

 to the tubercles. If a diseased potato be cut, the parts attacked 

 can be discerned with the naked eye by their yellow color, and 

 they emit a marked fungous odor; the tissue of these parts is 

 softened and easily separated. Very thin slices under the micro- 

 scope exhibit at the limits of the change a slightly yellow liquid, 

 which insinuates itself into the intercellular spaces, and gradually 

 envelopes almost the whole periphery of the cells. In the parts 

 strongly attacked it destroys the adherence of the cells; and this 

 explains the easy disaggregation of the tissue. The cells, by de- 

 grees invaded by the yellow liquid, preserve their grains of starch 

 intact. When the dislocation of the cells has made new progress, 

 the mass of the tissue becomes pulpy, semifluid, whitish, or of a 

 brown color more or less deep; a great number of the cells are 

 destroyed, even broken up. In this state, however, the grains of 



