120 dr davy's observations on the cuticle. 



evaporation as the removal of the whole of the integuments, and is as fatal to 

 life ; the colour, too, which the tuber acquires, with change of form from its re- 

 moval, are circumstances which seem worthy of note.* 



On the 26th September, two apples of the same kind, not sweet, were selected ; 

 one unpeeled (No. 1), weighed 933 - 5 grs ; the other peeled (No. 2), weighed 

 1051 grs. They were suspended by their stalk in a room, the temperature of 

 which varied from about 80° to 55° and 50°, during the time of trial. The results 

 of the weighing from time to time are given in the following table, viz., the loss 

 per cent. : — 



October I. No. 1 bad lost 18 per cent , No. 2, 13-9 



11. 



55 



8-1 



1$ 



„ 61-5 



30. 



»s 



14-2 



if 



„ 80-8 



November 6. 



55 



17-7 



55 



„ 824t 



12. 



>5 



18-9 



V 





20. 



)• 



21-8 



55 





26. 



55 



24-2 



95 





December 2. 



55 



265 



35 





14 



»' 



30-1 







30. 



55 



337 



5> 





On the 30th December, No. 1 was shrivelled ; it retained its colour, a greenish 

 hue, and, cut into, was found free from decay. No. 2 had become very much 

 shrunk, had acquired a brown colour, and a slight degree of sweetness. 



I need not dwell further on the remarkable manner in which the dessication 

 of vegetable substances preserves them from chemical change, and in many 

 instances for a long period ; but I must express regret that a process so simple, 

 and in other countries, especially France and the United States of America, so 

 much used, is not more employed in Great Britain. By means of it, the families 

 of the labouring class might secure to themselves throughout the year a greater 

 variety of food at a cheap rate ; the apple for instance ; several vegetables, such 

 as the carrot, potato, &c. — a variety equally recommended by two qualities, which 

 happily are seldom disjoined, those of agreeableness and wholesomeness.+ 



* In another experiment, begun on 27th October 1863, the results were much the same, with 

 this difference, that, on the 17th March 1864, the unpeeled potato was removed from the light into 

 a dark cupboard, and covered with a small inverted porcelain jar. There it has vegetated ; it has 

 shot out many branches, all but the largest of which are white ; it is of a light purple ; attached to 

 them are many well-formed tubers. Now, March 15, 1865, the weight of the potato is reduced from 

 what it was at first, viz., 9005 grs., to 331 grs. It has no terminal leaflets. There are seventeen 

 small tubers connected with it ; all are of an oval form, like the parent tuber ; the largest is -4 inch 

 in length. All of them are throwing out shoots, and they are most easily detached. 



f Its weight afterwards fluctuated a little, according to the hygroscopic state of the atmo- 

 sphere. 



J Sliced apples exposed to the air dry rapidly, as do also sliced potatoes and carrots ; and if 

 put up in paper bags in a dry place, they will keep fit for use for a long time. No vegetable that 

 I am acquainted with undergoes change more rapidly than the sweet potato [Batatas edulis), yet 

 when sliced and dried, as I have found by experience, it may be kept for years unaltered. I have 

 some thus preserved, which I brought from the West Indies in 1848. 



