HARD WICKE ' S S CIENCE- G SSIP. 



iGj 



spirit varnish and have bought repeatedly negative 

 varnish at three times the price, and should be pleased 

 to know if the varnish I name would do. Surely 

 there is nothing in the spirit varnish that could 

 be unsuitable, and nothing in the so-called negative 

 varnish that is absent from the best white hard spirit 

 varnish. That which I have is the best to be obtained, 

 made by the most reputed varnish manufacturers. 

 — H. Fi slier. 



Saccharine. — Referring to the article on Saccha- 

 rine for May, can Mr. Wicks say why Saccharine is 

 precvibed for patients suffering from Diabetes when 

 sugar is considered harmful? — Rev. H. Whittaker, 



Peterborough. 



Yew-Trees, their Age, &c. — You were good 

 enough to admit into your January number a letter 

 of mine inviting discussion on yew-trees, and the 

 mode of ascertaining their age. In your February 

 number three letters appear in reply. I wish, first of 

 all, to thank the writers. In 1 the first letter, A. G. 

 Tansley calls my attention to " the two finest yews 

 in the Malvern country, in Cradley churchyard," and 

 adds that "the largest is 26 feet in circumference," 

 quoting a "Botany of Malvern " as his authority. I 

 have since measured the Cradley yews, and found 

 one 17 feet 7 inches, and the other 17 feet 9 inches 

 in circumference, making allowance in the one case 

 for a portion of trunk which had evidently dis- 

 appeared. J. Saunders, Luton, the writer of the 

 second letter, is good enough to promise the measure- 

 ment of some Bedfordshire yews. Both these writers, 

 however, seem to object to the measurement of the 

 diameter instead of the radius. Allow me to explain 

 that I used the word "line " in its arithmetical sense, 

 as meaning T ^th of an inch, and without any reference 

 whatever to the concentric rings, and I adopted the 

 diameter as simply a convenient mode of expressing 

 the size. I have to thank W. E. Windus for calling 

 attention to the Crowhurst (Sussex) tree, and for the 

 promise of the photograph, a copy of which I have 

 since received. Your correspondent F. C. D. B. in 

 the March number, besides giving particulars of the 

 yew at Ankerwyke House, also evidently thinks the 

 size may be conveniently expressed by the length of 

 the diameter. And this is, of course, the same thing 

 as measuring the circumference and taking one-third 

 of it as representing the diameter, only in taking the 

 circumference it must always be the smallest circum- 

 ference, whether it is three feet or more or less from 

 the ground being a matter of no moment. As an 

 authority for taking a line of diameter to represent a 

 yew, I refer to Mons. A. P. de Candolle's remarks 

 on the subject in Dr. Pye Smith's "Geology and 

 Scripture," as follows: — "Of all European trees, 

 the yew appears to me to be that which attains the 

 greatest age. ... If for very old yews we take the 

 mean of one line a year, it is probable that we are 

 below the truth " (it is necessary, however, here to 

 add that he takes the line to be T ' th of an inch), 

 " and that in reckoning the number of their years of 

 age as equal to that of their lines of diameter, we 

 make them younger than they are." He continues : 

 " Now I have become acquainted with the measure- 

 ment of four celebrated yews in England. That of 

 Fountain Abbey, .... of which we have historical 

 notices in 1 133, was, according to Pennant, in 1770, 

 1214 lines in diameter, which will give above 1200 

 years of age. That in the churchyard of Crowhurst, 

 Surrey, is stated by Evelyn, in 1660, to be 1287 lines 

 of diameter. . . . That of Fotheringhall, in Scotland, 

 had in 1770 a diameter of 25SS lines, and its age is 



consequently twenty- five to twenty-six centuries. 

 That in the churchyard of Braburn, Kent, had in 

 1660 a diameter of 28S0 lines ; if, then, it be still in 

 existence, it must have reached 3000 years." The 

 Braburn yew, I may add, is no longer in existence. 

 In 1660, when Evelyn measured it, he found it 

 58 feet in circumference. Balfour, in his "Botany 

 and Religion," adopts Mons. de Candolle's list of 

 " Remarkable Trees, the ages of which have been 

 ascertained," and gives 2880 years as the greatest 

 of the yew. In an article in " Eng. Cyc." on the 

 age of trees, there is a " Table of the Rate of Increase 

 in Diameter of certain Exogenous Trees expressed in 

 Lines," and amongst them a yew seventy-one years 

 old, whose diameter was 695 lines. — P. J. 



NOTICES TO CORRESPONDENTS. 



To Correspondents and Exchangers. — As we now 

 publish Science-Gossip earlier than formerly, we cannot un- 

 dertake to insert in the following number any communications 

 which reach us later than the 8th of the previous month. 



To Anonymous Querists. — We must adhere to our rule of 

 not noticing queries which do not bear the writers' names. 



To Dealers and Others. — We are always glad to treat 

 dealers in natural history objects on the same fair and general 

 ground as amateurs, in so far as the "exchanges" offered are fair 

 exchanges. But it is evident that, when their offers are simply 

 disguised advertisements, for the purpose of evading the cost of 

 advertising, an advantage is taken of our gratuitous insertion of 

 " exchanges " which cannot be tolerated. 



We request that all exchanges may be signed with name (or 

 initials) and full address at the end. 



J. A. H. and others. — The author of "Sagacity and Morality 

 of Plants" was slightly in error in referring (page 31) to Mr. 

 Grant Allen's work on "The Shapes of Leaves." The'subject 

 was treated upon by Mr. Allen in "Nature" (1883) under this 

 title, but we believe the papers have not been republished. 



J. T. Balcomb. — Thanks for your specimens. We will bear 

 the matter well in mind. 



M. E. Pope. — Many thanks for your kindly interest in the 

 old " Science-Gossip." We wish all our subscribers were as 

 good proselytisers ! 



C. Wilson (Southport). — The plant is Claytonia pcrfoliata. 

 — a Canadian species, and an excellent salad plant, containing 

 oxalic acid in its leaves. 



G. Grierson. — Write to Dr. M. C. Cooke, 146 Junction 

 Road, Upper Holloway, London, N.W. 



Geo. Campbell. — Apply to the editor of the Geologists' As- 

 sociation, Professor Boulger, 18 Ladbroke Grove, London, W., 

 for the paper on "Agates." 



E. Browne and others. — Mr. Brunetti's address is 129 

 Grosvenor Park, Camberwell, S.E. 



J. B. — We expect you refer to the late Dr. Lankester's " Uses 

 of Animals to Man " for the paper on Tannin. If so, enquire 

 of Messrs. W. H. Allen, Waterloo Place. You will find good 

 papers on Tannin in the last edition of Professor Johnson's 

 " Chemistry of Common Life," edited by Professor Church. 



W. Gyngell. — Address, _ the " American Naturalist," 501 

 Chestnut Street, Philadelphia, for exchange. 



W. L. K.— Apply to Mr. King, Sea Horse House, Portland 

 Road, London. 



EXCHANGES. 



Marine shells, rubbings of memorial brasses, and curios ; 

 what offers? Will send list of either if wished. — Archibald Hy. 

 McBean, S. Denys, Southampton. 



Wanted, eggs, in clutches, of rare British birds ; also 

 cuckoo's eggs, with full data. Offered, a good exchange in 

 insects, eggs, or shells. — W. K. Mann, Clifton, Bristol. 



Rare Scotch and Irish mosses and hepatics offered in ex- 

 change for others. Special desiderata, 26, 27, 99, 106, 109, 121, 

 135, 147, 154, 156, 166, 169, 173, 183, 187.— W. B. Waterfall, 

 Thirlmere, Redland Green, Bristol. 



Mosses and hepatics offered in exchange for slides of same. 

 — W. B. Waterfall, Redland Green, Bristol. 



What offers in unmounted micro-material for first-class slides 

 of the following : arranged foramimfera (50 varieties) ; sections 

 of species of echinoderms (20 varieties) ; sections of bone and 

 teeth (in Canada balsam), showing the lacuna? and canaliculi ; 



