INJURY BY DISINFECTANTS TO SEEDS AND ROOTS. 6 
1.83. Repeated parallel tests of C. P. and commercial sulphuric acid 
failed to develop any difference in their effect on the seed beds. A 
part of the hydrochloric and nitric acids used was C. P. and part com- 
mercial. The ammonia used was the strongest commercial ammonia 
water obtainable from local druggists (ordinarily 26° Beaume). The 
formaldehyde used was the so-called 40 per cent commercial solution. 
Because of the need of distinguishing between pure formaldehyde and 
this commercial solution the latter will be referred to as formalin. 
The general use of the term " formalin" for the commercial solution 
appears to have become approved by custom/ despite the fact that 
this term formerly applied only to the product of an English firm. 
The lime-sulphur used was a commercial solution with a specific 
gravity of 1.31. The mercuric chlorid used was C. P. and the cupric 
sulphate was the fully hydrated crystalline form. The copper acetate 
was neutral, containing a single molecule of crystallization water. 
The zinc chlorid was a technical grade, granular, guaranteed from 95 
to 98 per cent pure. All lime used was air-slaked. 
The unit of measure used throughout is the fluid ounce (29.574 c. c.) 
for the acids, formalin, ammonia, and lime-sulphur solution, and the 
avoirdupois ounce (28.35 grams) for the other substances. Except 
where otherwise stated, all of the disinfectants were applied in aqueous 
solution. When lime was used the powder was spread dry on the 
surface of the bed and was worked into the upper 2 or 3 inches with 
a rake. Two or three pints of water per square foot of seed bed was 
found a convenient vehicle for applying the disinfectants. Because 
of the variable moisture content of the soil the degree of dilution of 
the solution before application is not of the greatest significance. 
The amount of the disinfectant used per square foot of soil surface 
is given in all cases as the measure of the strength of the treatment. 
PLANTS UPON WHICH OBSERVATIONS WERE MADE. 
The seed beds on which disinfectants were used were sown with 
different species of pine. Jack pine (Pinus divaricata) was the species 
used in most of the work, while western yellow pine (P. ponderosa), 
Norway pine (P. resinosa), and Corsican pine (P. laricio) were also 
used, the relative frequency being in the order named. 
Weeds of various types appeared in the seed beds in addition to 
the pines, and data as to their tolerance of disinfectants were also 
obtained. Cryptogams were represented by a large-stalked species of 
Equisetum, the algaa conspicuous in many nurseries being present to 
but a slight extent. Monocotyledons were represented by various 
grasses, Eragrostis cilianensis 2 being much the most common, while 
Echinochloa crus-gaUi, Panicum harhipulvinatum, 2 and CTiaetochloa 
iPerkin, W. H., and Kipping, F. S. Organic chemistry, new ed., p. 124. London, 1911. See also 
Webster's New International Dictionary, 1913. 
2 Determinations made by Mr. P. L. Ricker. 
