MR. TOWERS ON THE POTATO DISEASE. 



31 



small iron rods. The material used for covering them may be 

 the asphalte felt now manufactured extensively for roofing pur- 

 poses, or strong brown paper coated with tar ; the latter is used 

 extensively in Germany for this purpose, and is found to be very 

 durable and cheap ; it is there even preferred to every other 

 material. 



Though the covering of hot-houses has been already practised 

 in some cases, I am not aware of any one having adopted a close 

 covering with the view to facilitate ventilation or aeration during 

 the night. It appears to me that the circulation of air, secured 

 by the means here proposed, would have much influence in ex- 

 cluding cold, whilst at the same time it would prevent the interior 

 from becoming too warm and close. 



5, Gloucester -place, RegenV s-parh. 



III. — Facts connected with the Potato Disease. By Mr. John 

 Towers, C.M.H.S. 



(Communicated October 23, 1846.) 



It might appear superfluous to dwell longer on an infliction 

 which has formed the subject-matter, as it were, of all the peri- 

 odicals on rural affairs for above twelve months. Nevertheless, 

 as a member of the London Horticultural Society, I should not 

 be satisfied were I to withhold the communication of experi- 

 ments and results performed and obtained by myself, without 

 any interference which could affect the condition of either. 



In common with others, my then extensive and most beautiful 

 winter crop became affected in August, 1845. The earlier 

 varieties of ash-leaved, middle, prolific -kidney, and round pota- 

 toes (all white), suffered little. I caused the haulm of all the 

 winter reds to be cut over and burnt, but that of the Champions 

 and " July" variety (so called) was left untouched. During the 

 dry weather of October all were dug. The crop would have 

 been great, but a sixth part, or thereabout, was either so decayed 

 or affected as to be deemed worthless. The remainder was stored 

 in a dry airy barn, but so covered by new straw and a rick-cloth 

 as to be quite secure from frost. 



The only circumstance of moment which I noted as then pecu- 

 liar to the disease of 1845 was the fermentation of the entire 

 cellular substance of a few of the largest tubers, even as they 

 were digged. It bore every appearance of strong working yeast — 

 frothy, and in texture nearly adhesive and ropy as birdlime — the 

 fermenting pulp emitting highly foetid ammoniacal gas, dis- 

 coverable by the approach of a glass stopper moistened by muri- 



