EFFECTS OF SAWDUST ON FISH LIFE 



41 



SESSIONAL PAPER No. 22a 



spirits of turpentine by distillation of the crude turpentine which runs away from the 

 trees when they are tapped. The residue after the distillation is known as resin. 



Fig. 3. — Cells showing cell-wall; protoplasmic 

 contents with cell-sap. 



Now the source of the poison in the yellowish brown water is unquestionably the 

 material stored in the wood cells. As each cell or vessel is microscopic and contains 

 only a very small quantity of poisonous material, and as the cell wall must be broken 

 open in order to let out the cell contents, it follows that the greater the number of cells 

 that are opened, the greater will be the quantity of turpentine, tanin, &c., poured out. 

 Hence a saw-log completely converted into sawdust would give out the maximum of 

 poison, whereas a similar log sawn into boards, slabs and edgings would give out a 

 much less quantity. Pulp mills will give out the maximum of stored material. So will 

 beet-sugar factories. 



The total waste in manufacturing saw-logs into inch boards varies from 25 per 

 cent to 35 per cent of the whole log. Of this total waste, about 13 per cent is sawdust. 

 The proportion of refuse varies (1) with the size of the logs, (2) with the kind of 

 lumber into which the logs are sawn, and (3) with the width of the cut made by the 

 saw*. 



PULP MILL POISON. 



M.J St. Andrew's experiments determined the percentage of poison from a sulphite 

 pulp mill which is fatal to fish life, but so far as I know, the percentage of poison from 

 a mechanical mill has never been determined. A provisional conclusion, however, raay 

 be fairly based upon some of my experiments to be described later in this paper. 



QUANTITATIVE DETERMINATIONS. 



A quantitative determination of the solid matter contained in the yellowish 

 brown water was made by evaporating 1,000 c.c. of it, at 100° C, in a platinum cru- 

 cible, and then weighing the rest. 



The following results were obtained from white pine solution: — 



M.gs. 



1. Solid matter from 1000 c.c. water, the sawdust soaking for 



four days 1160 



2. Same sawdust with the first water filtered off, and fresh 



water added and allowed to stand for five days. Solid. . 260 



CEDAR SAWDUST. 



1. Solid matter from 1000 c.c. water, the cedar sawdust soak- 



ing for four days 1220 



2. Same sawdtist with first water filtered ofi, fresh water added 



and allowed to stand five days 470 



3. Same operation repeated. Soaking five days 270 



