98 Extracts from the Journals. Jan., 



er to obviate any chance of fallacy in these results, I requested 

 Mr. Scanlan to repeat my fermentation experiments on a some- 

 what larger scale than mine, with diseased potatoes found in his 

 own neighborhood, at the extremity of London, opposite to my 

 residence. He has accordingly made several similar researches, 

 with like results, of which I shall give the particulars of one only. 

 Two and a half pounds of the expressed juice of such potatoes as 

 aje now used solely for feeding cattle, corresponding to three and 

 one-third pounds of the entire tubers, were mixed with a small 

 portion of yeast, and set to ferment in half-filled bottles. The ac- 

 tion soon became so vigorous that the barm rose to the brim ot 

 the bottles. At the end of thirty-six hours, the liquor, having 

 become nearly tranquil, was distilled, and afforded 5000 water- 

 grain measures of an alcoholic liquid, of specific gravity of 0,988, 

 containing, by Tralle's table, eight per cent of absolute alcohol, 

 equivalent to sixteen of sugar. ]6-j-50:^800 grains, may be 

 regarded as the quantity of sugar indicated by this experiment in 

 three and a half pounds of the diseased potatoes, or in 23,333 

 grains, being nearly three and a half per cent. In other samples 

 I found, as above stated, results indicating considerably more su- 

 gar, the proportion being very variable, according to the state of 

 the disease. The vinous spirit produced is by no means disagree- 

 able in taste or flavor, and may be easily rectified into excellent 

 alcohol, fit for every purpose of arts, manufactures, and pharmacy. 

 Were it not for the oppressive laws of the excise, suflScient alco- 

 hol might thus be obtained this season for the uses of a temperate 

 people, reserving an equivalent portion of grain from the whisky 

 manufacture for their sustenance. The residual cake of the dis- 

 eased potato is well adapted for feeding cattle, the morbid juices 

 having been separated, and it may be so dried as to keep un- 

 changed for a moderate length of time. 



In all the diseased potatoes which I have examined with the 

 microscope, the fibres of a fungus, called botrytis from its grape- 

 like form, or of one called uredo tuberosum; may be observed ra- 

 mifying round the cells which enclose the starchy corpuscles. 

 Now these plants, however minute, are not self-generated, but 

 must be produced by some seminal impregnation transported by 

 the atmosphere, and peculiarly adapted to fructify upon the sola- 

 num tuberosum. I would hence conclude, that the potato disease 

 is a peculiar vegeto-pestilence, diffused generally through the at- 

 mosphere, whose ravages have been favored by the sunless hu- 

 mudity of the last season, as the predisposing, but not as the ex- 

 citing, cause. The proximate cause again, in medical language, 

 or the essence of the morbid state, is the fungous inmate of the 

 tuber, from seminal impregnation of the stem, which so paralyzes 

 the vitality of the plant, that a portion of the starch and albumen 



