480 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



[ June 27, 1865. 



its volume of water, and always in the afternoon when the 

 sun has lost much of its power. I must remark that the 

 drainings used for this pm-pose contain no minary matter 

 except that derived from the solid manure. 



All these liquids are used of the same temperature as 

 that of the house, the liquid being heated and strained 

 through a muslin or tiffany bag, so that dirt may not get 

 into the syringe. Some discrimination is necessary in using 

 the mamu-e water for syi-inging purposes. When the leaves 

 of Vines are young, and consquently tender, it should be 

 diluted one-tliii'd more, and the same for Melons, Cucumbers, 

 and all plants of which the leaves are young and soon 

 scorched. After they attain their full size it may be given 

 at the strength named, but always with the declining sun. 

 The clear liquid only is used for syringing with. 



I have used all the liquids named at four times the strength 

 stated above for filUng evaporating-troughs, but only for 

 destroying insects ; for I find that the ammoniacal vapour 

 when very strong is apt to scorch the leaves, particularly 

 when the air becomes surcharged with it and the sun is 

 powerful. I may also state that when the evaporating- 

 troughs arc filled to overflowing, and the liquid drips on the 

 hot pipes or flues, the air is so quickly filled with the vapour 

 that the leaves of Vines and simdar plants, especially when 

 young, are scorched. When, however, the leaves have 

 arrived at that stage at which red spider usually attacks 

 them there is no danger in using the liquid at four times 

 the strength, and as charging the atmosphere with ammo- 

 niacal vapour is necessary to destroy mealy bug and red 

 spider, that strength becomes a matter of necessity, other- 

 wise only weak doses are needed as invigorators, whilst 

 syringing the foliage renders it very distasteful to insects. 



Ammoniacal vapour, though desirable, should be used 

 with care. Smooth or plain-leaved plants, as Vines, Pigs, 

 Peaches, Plums, Cherries, Pines, Gardenias, Oranges, and 

 all those usually attacked by j-ed spider, will endure vapour 

 of doable the strength I have stated, and may safely be 

 syringed with the liquid after the leaves attain their full 

 size ; woolly and soft-textured leaves, as those of Gloxinias, 

 Azaleas (though not soft but hairy), Gesneras, and Pelar- 

 goniums, had better not be syringed, and should never be 

 exposed to a highly ammoniacal atmosphere. 



Finally, I would state my conviction of the little reliance 

 to be placed on ammonia alone, thinking it best applied 

 along with phosphates. I find the different salts of ammonia 

 vary so much in strength as to make their use unsafe. The 

 best that I liave used was a solution of ammonia made by 

 dissolving 1 lb. of carbonate of ammonia in a gallon of water, 

 keeping the solution in a close-stoppered bottle, and putting 

 a little in the evaporating-pans at the time of shutting up 

 the house. A pint was allowed for a house 30 by 18 feet, 

 5 feet high at the sides, and 12 feet from the centre to the 

 apex. I must admit that this sensibly invigorated the 

 foliage of the plants, it being larger, and the roots of Orchids 

 were more plentifully emitted, but there was not that 

 increased greenness in the leaves which is the characteristic 

 of an atmosphere manured with guano or sheep's dung in 

 solution. In fact, the foliage was not of so good a colour 

 as without the ammoniacal vapour. We gave it up and con- 

 verted the carbonate into the sulphate of ammonia by drop- 

 ping sulphuric acid into the solution till all bubbling ceased. 

 For stimulating the growth of plants, sulphate of ammonia 

 at the rate of 1 oz. to eight gallons of water, is, perhaps, 

 unequalled, it being applied the same as other liquid manures 

 to plants in a growing state. 



After giving it may not be out of place to ask for infor- 

 mation. Has the presence of ammonia been detected in at- 

 mospheric air by analysis ? Liebig says nay, and yet he notes 

 its presence in rain water and snow. There is every reason 

 to believe that it does exist in the atmosphere, and descends 

 with the dew and the rain ; • but if it bu traceable in water, 

 • That f4lHnj? <it Rotliamsted, In IIcrtfordRhire, twenty miloi from Lon- 

 don, hAfl t>ecn exumlnud by ProfCBi-or Way. He found (Kraina) in an 

 imperial gjl on In — 



Ammonia. Nitric acid. 



Joly 0.1 01 ... (1017 



AlJKU't 0,080 ... O.OliO 



Drpieinber ... 0.085 ... 0.021 



iicUibfr nei ,,. 0.03C 



Niivrmbcr ...0 054 ... 0.0,8 



Uecembcr 0.007 ... 0.017 



—^Htienct and fraetice o/ Oarffen'fnt;, page 74. J i 





Anininla. 



Nitric acid. 



Janoiry.. 



... OiB2 



.. 0.017 



Ket^riiary 



... 11.104 



.. O.OII 



March .. 



... n.o8» 



.. 021 



April 



... \n 



.. 0.086 



May 



.. .080 



.. 0.03i 



June 



... 1>6 



.. 0.080 



why not in air prior to rain, when the air is often nearly 

 saturated with moisture? Fact proves the presence of it. or 

 some other powevful stimulant descending at night with the 

 dew, and exciting plants into growth days even before actual 

 rain falls, and if it come a shower without wetting the earth 

 beyond the surface, what an alteration it makes in the face 

 of nature. The drooping leaves revive, the buds burst their 

 scales, flower-buds swell and await the first gleam of sun- 

 shine to unfold theii' beauties. Then rain water from an 

 open tank some days after falling, is less invigorating than 

 fresh, winter rain water less marked in its effects on vege- 

 tation than that which falls in spring and summer. Snow 

 water is the softest of water, it contains ammonia. — G. 

 Abbey. 



VAEIATION OP COLOUR IN HYDEANGEA 

 FLOW^EES. 



I HAVE read with much interest Mr. Robson's article on 

 the Hydrangea, but I am sorry it does not go further to- 

 wards solving the mystery as to the cause of the flowers 

 being occasionally blue ; and I hope the discussion he has 

 invited may give us a little more light on the subject, but I 

 am not very sanguine on that point, as I think that if blue 

 flowers could be produced at will some of our great Covent 

 Garden florists would have made a display of such before this. 

 The blue-flowered Hydrangea has been a great mystery to 

 me from a boy. I have seen a plant produce blue flowers 

 one year and pink the next, or, perhaps, a year or two pink, 

 then blue, and so on ; but I never saw a very young plant 

 with blue flowers. What seems more curious than all was 

 one large plant I knew that used to produce blue flowers on 

 one side and pink on the other — the most shaded side pro- 

 duced the blue flowers. Has Mr. Robson ever seen or heard 

 of such an occurrence before ? 



It is not at all uncommon to see the Hydrangea with blue 

 flowers in the neighbourhood of which I am writing — 

 namely, on the borders of the Forest of Dean, in Gloucester- 

 shire, where I have seen some plants with pink, others, 

 perhaps in the same bed or border, with blue flowers, and to 

 all appearance in precisely the same sort of soil, which was 

 a heavy loam, resting on a sort of red sandstone, where the 

 Foxglove was quite at home ; and so far agreeing with what 

 Mr. Robson says of the Rhododendron. 



The Hydrangea used to bo cultivated much more in that 

 part of England than in the others to which I have been since 

 leaving there — I mean as an out-door plant. Mr. Robson 

 says it is quite hardy, but I am not quite sure of this ; for I 

 have seen it killed in several places in the winter, but in 

 some only killed down to the ground, yet rendered useless 

 as a flowering plant. Here, and at a place in Kent (near 

 Ashford), I have found they will not stand the winter — at 

 least not their shoots. — J. Bryan, Heydon ifotwe, Eoyston. 



[Some years since the late Mr. Beaton wrote to us upon 

 this subject, as follows: — 



" There is one disadvantage in August-made cuttings of 

 the Hydrangea, which is, that the flowers of them come all 

 of one colour, and that the same as that of the parent plant, 

 whether it be blue or pink ; but those made in February 

 may be made to flower blue or pink at will. If the mother 

 plant produced blue flowers in the former seasons, and you 

 force it in February, cut. olf your cuttings as soon as they 

 make three joints, and when they are i-ooted place them in 

 a rich, light compost, say one-half leaf-mould or very rotten 

 dung, and the rest of any good garden soil, they never fail 

 to produce pink flowers; whereas, if taken from a pink- 

 Dowering parent, and after rooting growing them in strong 

 yellow loam, with about a sixth part of iron filings mixed 

 with it instead of sand, nine out of ten of them will produce 

 blue flowers. I have proved this over and over again, and 

 have seen it in other hands, but I never could get an August 

 cutting to differ in colour from that of the parent plant. 

 The reason seems to be that the juices of the parent plant 

 have already, by a season's growth, formed the substance, 

 or the organised matter, as physiologists call il., out of 

 which flowers are produced, so that no after-treatment is able 

 to counteract the effect ; wlicreas if cuttings are separated 

 from a plant at so early an age as when they only attain a 

 few inches in length, and are then made to grow in iion lust 



