April 6, 1883.] 



• KNOW^LEDGE • 



211 



on each day. Gradnally I read more than two pages, and read as 

 maoh aa I conid without losing interest ; but I made it a rule only 

 to read when in the mood. I found this made an immense 

 difference, for when I forced myself at times to read, I had all my 

 trouble over aeain the next day, my mind not having retained a 

 single word. I have been working now for three months at my 

 leisure, and this is the result, — I have mastered n great many new 

 words, most of the idioms, and have a fair knowledge of the eon- 

 Btmction of the language. I can also translate at ease, only at 

 times making use of a dictionary. 



I think this is a groat deal gained, with very little trouble, and in 

 a short time. I had learnt German for nearly four years, after 

 the usual method, and at the end of that time, though 1 had worked 

 bard, I could not translate a a page of German without a great 

 deal of trouble. M. P. 



BETROCESSION OF THE SEA. 



[779] — I do not believe that " A Southport Kesident " is correct 

 in saying that there has been no retrocession of the sea for the last 

 fifty years. My own opinion is that the sand is gr.idually hut 

 surely gaining on the sea, and has been so doing for a long period. 

 At the present moment the Corporation of Southport are petitioning 

 against I'rcston being allowed to build a sea-wall at the entrance to 

 the estuary of the Kibble, and are stating that if this should be done 

 the shallow channel leading to Southport Pier would be silted up 

 Tery quickly, and Southport itself left high and dry as an inland 

 town. ' G. JI. 



A NEW ZEALAND GUM. 



[780] — The following extract from Martin's "British Colonies" 

 contains information regarding the above which may be of interest 

 to Mr. Joseph Clark : — 



" The habitat of the majestic Dammara Australis, or Kauri, is 

 limited to the northern extremity of the North Island, and has a 

 lange of less than three degrees of latitude and ono degree of longi- 

 tude ; even in these narrow boundaries it is by no means a cornnton 

 tree, but is entirely confined to hilly situations. The smooth, grey, 

 oolumnar stems measure from thirty to forty feet in circumference, 

 and maintain very nearly the same girth through a length of from 

 sixty to even ninety feet. The crown of the tree, where it is ir- 

 regularly branched, is small and out of proportion to the trunk ; 

 and the foliage is likewise diminutive as compared with the 

 branches. 



" The wood is very light in proportion to its great strength and 

 durability ; it is, therefore, admirably adapted for apars and masts. 

 The land on which it grows, even when cleared, is useless for occu- 

 pation, from the rugged nature of the ground, and from the quality 

 of the soil. It is one of the most remarkable jihenomena in botany 

 that such an immense tree should flourish wliere it could scarcely 

 be supposed able to take root. The rosin which it exudes is very 

 bard, and forms large solid masses at the base of the tree. It is 

 generally of a whitish colour, but through age and, as it would 

 ■eem, exposure to the sea-water, it assumes the golden-yellow colour 

 of amber, becomes transparent, and very closely resembles that 

 •nbstance. The Kauri i.9 the only coniferous pine in Now Zealand." 



W. MooB, Jan. 



A NEW NARCISSUS. 



[781] — If high art is not beyond your scope, you may find this 

 interesting. The Government School of Art at South Kensington 

 supplies to ladies (for a consideration) drawings of Howers, &c., 

 traced in outline upon velvet or the like, upon which the ladies may 

 embroider with silks of appropriate colours. Such a drawing in 

 ontline on black velvet has just been shown to me by a lady. It 

 Wpresents a group of bulbous flowers — tulip, narcissus, &c. A 

 narcissus, plainly indicated by foliage, stalk, nectary, &c., is drawn 

 with five petals — a plain, unabashed, .full-faced jientagon ! Can 

 yon tell me whether this is high art ? It certainly is not nature. 



G. O. E. 



A VEIN THEORY IN BOTANY. 



[782] — Although the most important function of your journal 

 may he the diffusion of knowledge, yet I hope you will hold it 

 ilW panJonable for me to ask yon to give publication to a point of a 



ri"^ seientific lecture, of a kind which 1 should have hoped was well- 



nigh obsolete in these days of well-weighed facts. The lecture was 

 gwen by Mr. A. Tylor at the London Institution on Monday, the 

 19th inst; the title, "jSIstheticism, as Displayed by Animals and 



Plants." The one good point was found in the illustrations, which 

 were well executed, but the lecture was frivolous in the extreme. 

 For nearly lialf-an-honr had wo to listen to such nonsense as this : 

 Mr. Tylor stated that the somewhat zigzag course pursued by the 

 midrib of a leaf was caused by tho force of the current from the 

 alternate veins on either side, and illustrated it by reference to the 

 fact that the course of a river is so iiillucnced by tributary streams. 

 One would liavo thought that a minute's consideration would have 

 shown him that during tho composition of tho leaf the current runs 

 tho wrong way for his fact. Ho might, like Washington Irving's 

 philosopher, who, finding that the world would not accommodate 

 itself to his theory of revolution, wisely determine to accommodate 

 his theory to tho world. 



The phantom theory above alluded to was reiterated with wearisome 

 pertinacity ; indeed, had not Mr. Tylor made this the chief point 

 in his lecture, it would not have been worth writing about ; but 

 such a statement, given with such assurance in the London Insti- 

 tution, might mislead many who listened to learn. The rest of the 

 time was mainly devoted to a narration of a few plain natural 

 facts, without any attempt being made to demonstrate irhij things 

 were so. C. M. A. 



POTATOES. 



[783]— In Vol. I., Nos. 20 and 29, "Farmer" states his belief 

 that the unpalatableness of frozen potatoes is due to the " frost 

 coming oat," for when the potatoes are roasted thoy will be good 

 food, but not if only boiled. It is somewhat dilKcult to understand 

 what is exactly meant by the expression " frost coming out," but 

 though it is in common use, yet the idea that it conveys to my 

 mind is but vague. 



However, as '' Farmer" seems to be interested in the subject, I 

 will put before him the chief points in the latest researches made 

 in this direction by Dr. II. Miiller. 



Tho interior parts of the potato are not frozen until the tempe- 

 rature has sunk to 200° P., and if this temperature has been 

 rapidly and suddenly attained, as by exposure to the open air, 

 sugar is not formed, but on tho other hand when the tuber is but 

 slowly cooled down to its freezing point, a formation of sugar is 

 observed ; it is not necessary for this production that the actual 

 freezing point be reached, but only that the temperature should 

 slowly and gradually sink ; also the conversion of the starch pro- 

 ceeds' at all temperatures between 32° and 26'C'' ; in ono case, 

 potatoes were kept for thirty days at 32°, at the end of which time, 

 12 per cent, of the starch had been converted, but the actual amount 

 of sugar formed varies with each individual tuber, and those which 

 have the highest percentage of moisture present in them are the 

 more readily sweetened. It has been stated that the alteration of 

 the starch occurs at 32°, but it must not be supposed that there is 

 no change going on at higher temperatures ; sugar is formed above 

 32°, but it will be shown later on why it does not make itself so 

 evident. 



Now for the cause of the formation of sugar, and the reasons 

 why it is, so to speak, stored at low temperatures only. There is 

 present in the potato a ferment resembling diastase, or the ferment 

 of malt, which converts starch into sugar at all times, and tho 

 jjroduct thus formed is required for the growth of the protoplasm ; 

 but the cold checks the development of tho protoplasm, whilst it 

 has no very appreciable effect in tho action of tho ferment. Hence 

 sugar continues to be formed, but not consumed, and it is only at 

 comparatively high temperatures that production and consumption 

 are equal, in which case potatoes keep or remain apparently un- 

 changed. The process which thus goes on continuously involves a 

 distinct loss of part of the potato, but it must be remembered that, 

 although loss has occurred, yet the tuber is not valueless, for the 

 principal part of the nourishing portion (tho albumen) still 

 remains. It is curious that the sugar so readily disappears when 

 the tubers are kept for some time at a high temperature— say 68°. 

 Knowing this, wo may conclude that it is advi.sablo before cooking 

 a sweetened potato to keep it for several hours in a warm place 

 after which it may be cooked, and be indistinguishable from any 

 other ; but it is well known that it is useless to boil it while sweet, 

 as only a part of tho sugar is removed ; moreover, some of the 

 nutritious .albumen is at tho same time boiled out and lost. Per- 

 h.aps " Farmer," when making his experiments in boiling and 

 roasting, did not submit both samples to the same previous treat- 

 ment. With the material at pre.sent at hand I do not attempt to 

 account for the great differences which ho observed and recorded, 

 but is it not possible that he plunged one of his frozen potatoes 

 straight into the boiling water, whilst the other was kejit until such 

 time as the hot wood ashes were ready ? I venture to suggest an 

 answer to the query concerning the difference between a waxy and 

 a floury potato, but my suggestions arc only founded on a few- 

 analyses. In the waxy tuber the water is abnormally high, whilst 



