590 NEW JERSEY AGRICULTURAL COLLEGE 



''J-jV coinbining these oils in the proportion of T5 parts of pe- 

 troleum, 25 parts of combined vegetable oils, to which is added 8 

 to 10 parts of water and chemicals, the result is a neutral product, 

 Avhich is the nearest approach to a pure petroleum soap that has 

 ever been made. This, on account of its liquid oily appearance, is 

 called soluble petroleum." 



As to the cost of the material, the vegetable oils and chemicals 

 used, although forming only 20 per cent, to 25 per c^nt. of the 

 whole combination, cost four or live times as much as the 70 per 

 cent, petroleum which it contains. 



The petroleum which is used is of a brown colour, not mdike the 

 nsual appearance of ordinary crude, but it lacks the light gasolines 

 or naphthas, and is practically free from vaseline. In its raw state 

 it is therefore not nearly so diffuse as undiluted crude, and, on the 

 other hand, it leaves no penetrating greasy residue of vaseline or 

 paraffine to work into the plant cells. The vegetable oils dry out 

 before they soak in, but they have a tendency to bring the scales 

 into close contact with the bark, and the scurf may remain for an 

 entire season, sometimes giving the trees the appearance of being 

 l)iidly infested when not a living example can be found. At other 

 times the bark may clean up completely, leaving little or no scurf 

 remaining. As the material is completely soluble, all traces of 

 actual combined oil will be washed from the trees. It is almost 

 imi^ossilde to injure a dormant tree with "Scalecide," diluted in 

 any reasonable way, and successive applications do not produce a 

 <-umulative effect, because no residue remains to accumulate. 



A few points developed in reply to questions. Mr. Pratt admits 

 the possibility of a separation of the oils in combination under 

 conditions not well understood, but contends that the separation is 

 more apparent than real, and that a little shakiug up will restore 

 the Tiuiim. it is t(^ discount this unlikely separation that the di- 

 rectinn is ])laced on the outside of each package — "Shake well be- 

 fore u si ug." 



The water in combination is necessary to the emulsion, and the 

 loss of any considerable part of this water will impair its solu- 

 bility. Long standing in dry barrels may cause a loss of water, 

 and iience it will be better to test old material by placing a few 

 dro]>s in water before l)eginning to use. If it dissolves readily it 

 is all liulit; if there is any difHculty, add two cups of water to a 

 Larrel of "Scalecide" and stir thorou"hlv. This should restore the 



