May 0, 1012. 



The Weekly Florists* Review. 



95 



to plants even on moonlight nights, re- 

 markable as it may seem. This has 

 been so often demonstrated in experi- 

 ments, both at the Massachusetts Ex- 

 periment Station and elsewhere, that it 

 cannot longer be doubted. Fumigation 

 with cyanide, therefore, should not be 

 begun before dark, nor after dark 

 when there is bright moonlight, if a 

 strength of fumigation anywhere near 

 the maximum safe for the kind of 

 plant treated is to be used. 



Just why light should have an in- 

 jurious effect is by no means certain. 

 A few suggestions on this subject, 

 however, may not be out of place. It 

 is known that green plants in the light 

 take in carbonic acid and give ofiF oxy- 

 jjen. Both during the day and at night 

 the plant is also performing the reverse 

 process; that is, taking in oxygen and 

 •fiving off carbonic acid, though in the 

 daytime this is masked by the other 

 action, which is much the greater of 

 the two. Both processes are carried on 

 at the leaves, and in these, particularly 

 on the under surface, are numerous 

 openings known as stomata, sur- 

 rounded by guard cells which have the 

 power of enlarging and contracting 

 and thus of making the stomatal open- 

 ings smaller or larger. As the two 

 processes work together in the day- 

 time, it would seem as though the 

 stomata would at least be likely to be 

 more widely open at that time and be- 

 come smaller at night, and if so, the 

 smaller the openings the less opportun- 

 ity there would be for the entrance of 

 the gas into the leaf substance to in- 

 jure it. This, however, is as yet purely 

 speculative. 



Sodium, a Substitute for Potassium. 



During the last few years the possi- 

 bility of using cyanides other than 

 that of potassium has received some 

 consideration, as several of these are 

 well known to chemists. Of them all, 

 but one seems to be available for fumi- 

 gation, the others being too costly or 

 too diflRcult to obtain. This possible 

 substitute for potassium cyanide is 

 sodium cyanide. Our main commercial 

 deposits of the potassium compounds 

 necessary for the production of potas- 

 sium cyanide are located in Germany, 

 while the sodium compounds needed 

 for the manufacture of sodium cyanide 

 are widely distributed. Then, too, 

 sodium cyanide is now being manufac- 

 tured more abundantly than the other 

 and its unit price is at present rather 

 less than that of potassium cyanide. 

 From these facts it would seem that 

 the substitution of sodium cyanide for 

 potassium cyanide is worthy of some 

 consideration. 



Belative Strength of Sodium. 



Sodium cyanide is commonly com- 

 pared with potassium cyanide; that is, 

 the amount of cyanogen in the two is 

 the standard of comparison. Chemi- 

 cally pure potassium cyanide would, of 

 course, be 100 per cent pure, while chem- 

 ically pure sodium cyanide would be 

 133 per cfent pure. This rather remark- 

 able statement may be explained by 

 stating that, taking the same weights 

 of the two substances pure, there is 

 about one-third more cyanogen in the 

 sodium cyanide than in the potassium 

 salt. If, then, a pound of pure sodium 

 cyanide cost the same as a pound of 

 pure potassium cyanide, it would be 

 much more profitable to use the former, 

 because of the extra amount of hydro- 



Edmund R. Fry. 



cyanic acid gas it would produce. The 

 cost is not the same, however, the 

 sodium salt being the more expensive. 

 To obtain the same amount of gas 

 from either material at the same cost, 

 we can afford to pay one-fourth more 

 for the sodium salt, as this gives at 

 least one-fourth more of the gas. At 

 present the price for the sodium cy- 

 anide is not quite one-fourth more than 

 for the other kind, so there is a slight 

 saving by its use — perhaps two or 

 three cents per pound. 



Purity of Sodium Cyanide. 



The purity of the sodium cyanide is, 

 however, an important point. An im- 

 purity present in all but the highest 

 grades of this substance is sodium 

 chloride, common salt. Now, when sul- 

 phuric acid is added to such a grade of 

 cyanide it attacks the sodium cyanide, 

 producing sodium sulphate and hydro- 

 cyanic^icid gas. But some of the sul- 

 phuric acid attacks the sodium chlo- 

 ride, changing it into sodium sulphate 

 and hydrochloric acid. 



II2SO4 + 2NaCl = Na,S04 +2HC1. 



This hydrochloric acid immediately 

 attacks the hydrocyanic acid gas, de- 

 composing it to a great extent, and 

 thus largely preventing the fumigation. 

 Hence cyanide of sodium, to be suit- 

 able for fumigation, must be practi- 

 cally free from sodium chloride. 



Accordingly, if sodium cyanide is to 

 be used, it should be insisted that it 

 must be the 124 per cent pure, or 

 above this, and grades "100 per cent" 

 or less should be rejected. 



The Dose of Sodium Cyanide. 



With a cyanide containing one- 



fourth more cyanide than the potas- 

 sium salt, the dose should, of course, 

 be correspondingly reduced. If the dose 

 with potassium cyanide was one ounce 

 for a definite area, with sodium cyan- 

 ide it would become three quarters of 

 an ounce. 



The best proportions of chemicals to 

 use with sodium cyanide appear to be: 

 For each ounce of cyanide by weight, 

 one ami one-half fluid ounces of sul- 

 I)huric acid and two fluid ounces of 

 water. If the cyanide be of high grade 

 — 124 i>or cent or higher — and free 

 from soilium chloride, fumigation with 

 these jtroportions of materials should 

 be as successful as with the other cy- 

 anide. The time of exposure would be 

 the same. 



On the whole, sodium cyanide seems 

 t<» })romiae well as a substitute for po- 

 tassium cyanide, if only high grades 

 are used, so long as the price per 

 pound is less than one-fourth more 

 than the price for the same amount of 

 the other substances. 



E. B. FEY. 



E. R. Fry, of Rochester, N. Y., is one 

 of that city's most enterprising and ag- 

 gressive florists and growers. He is 

 noted among his acquaintances for his 

 genial personality, as well as for his 

 enthusiastic love of flowers and flori- 

 culture. He was born of English par- 

 entage in the town of Greece, N. Y., 

 near Rochester, and began work in the 

 florists' business when a mere boy. In 

 the early years he had a retail store on 

 Main street, Rochester, which he con- 

 ducted for five years. Then he bought 

 the property on Cottage street, where 

 he now has his residence and green- 



