256 NOTKS— BOTANY. 



valuable tuber has superseded the necessity for much other vegetable 

 food, for besides the nutritious qualities it contains an acid which is 

 a valuable antiscorbutic. 



When the potato disease first appeared in this country and in 

 Ireland, and there was quite a potato famine, in common with 

 many other medical men I saw a number of cases of land scurvy 

 characterised by bleeding from the gums and other parts. Potatoes 

 were then very bad and very scarce, but could still be obtained, and 

 I at once said in those cases, • You must eat them,' and found that 

 they soon cured my patients. 



NOTES—BOTANY. 



Tower Cress near Cockermouth.— During the month of June 1895 I had 



occasion to visit Isel about 4 miles from Cockermouth in a northerly direction, 

 and there I found a few plants of the Tower Cress {Turritis glabra Z.) in fruit. 

 Being in the neighbourhood again this year exactly at the same date, I visited the 

 spot in order to ascertain what had been the result of last years seeding. I found 

 some twenty to thirty huge and healthy plants, some not less than four feet in 

 height, and all again in perfect fruit. The plant is evidently a native here, and 

 has every chance to become more widely distributed. It would be interesting to 

 try and ascertain whether the herbage on the bank is removed in early summer 

 for fodder, hay, or either, and whether as a consequence the plant becomes 

 transferred to other localities or not. t fear I shall be unable to ascertain this.— 

 IiiLDERic Friend, Cockermouth, 16th June, 1896. 



Red Hawthorn, — The long period of drought which has occurred during 

 this spring and early summer has been productive of certain very visible 

 phenomena in the Kosacean flowers of this valley. Thus the petals of the 

 Common Hawthorn {Crahegus oxyacantha)^ which in other years and in many 

 individual shrubs well known to me have remained almost colourless from 

 budding to near final decay, have this year in the majority of cases exhibited 

 quite a glow of pink towards the latter part of their blooming period. It would 

 seem that a dry atmosphere and abundant sunlight have favoured the chemical 

 development of certain constituents of the petal sap. Under ordinary circum- 

 stances in this plant the substances which result from the waste-products of 

 chlorophyilian assimilation stop, as it were, at rutin, which may be regarded as an 

 intermediate tannoid compound incapable of producing red ot blue colours. 

 Rutin is found in considerable quantity in the white flowers of Hawthorn, Dog 

 Rose, Wild Cherry, etc., but these contain no or a mere trace of tannin, i.e., so 

 long as they remain white. When, however, as aforesaid, their corollas exhibit an 

 uncustomary tint of pink or red, it is time for a botanical chemist to look out and see 

 if anything unusual is contained therein. This accordingly I have been at pains to 

 do. I have made several analyses of this year's flowers, and in all cases where the 

 red colour has appeared there has been found, in addition to rutin, a very notable 

 quantity of tannin. The connection, therefore, between tannin and pigment W 

 clearly demonstrated. Thus also, to cite another instance, in the common Dog 

 Rose with a nearly white corolla there is no tannin ; while in the most deep- 

 tinted garden Rose there is abundant tannin and hardly any rutin or bitter 

 principle. It may be interesting to mention that the red colouring matter of the 

 Hawthorn flowers differs in no material particular from the tamiitar red of 

 the Rose ; both have undoubtedly the same chemical origin, but while the latter 

 is developed under the ordinary atmospheric conditions of British climate, the 

 former only appears when these are unusual and analogous to those which prevail 

 in a more northern latitude at a corresponding period of the year. — P. Q. KeegaN, 

 Fatterdale, Westmorland, July 91b, 1896. 



Natural©** 



