[13] PRESERVATION OF NETS AND SAILS. 307 



seeking to destroy the mildew fungus with alkalies, the growth of forms 

 favorable for putrefaction may be promoted. To quote from Duclaux :^ 



'^Acid liquids are in general more favorable to molds, to yeasts, and 

 to mycoderms; it is only very exceptionally and only en passant that mo- 

 bile forms are found in them, i. e., vibrios, bacteria, or monads. These 

 kinds appear, on the contrary, by preference, in neutral or alkaline 

 liquids, where the molds for their part have much trouble to live. The 

 mold Aspergillus, for example, grows freely on bread moistened with 

 vinegar, on the juice of lemon or slices of lemon, and on sour fruits and 

 liquors." 



I find a common impression that the sizing in new canvas attracts 

 mildew, i. e., that the mildew fungus finds a fit field for its support in 

 the sizing which has been introduced into the interstices of the canvas 

 at the factory. To avoid this difficulty some owners of vessels prefer 

 to bend their new sails in the autumn in order that the sizing may be 

 " worked out" of the canvas by the autumn and winter rains, at a time, 

 that is to say, when the weather is too cold for mildew to prosper. Old 

 sails are said to be comparatively exempt from mildew. The time-hon- 

 ored and universal custom of shaking out or hoisting sails in order that 

 they may dry after rain is one familiar method of preservation. It is 

 precisely because drying is frequently impracticable in some climates 

 that the tanning process is practised. 



It would be well to study practically whether the method of perma- 

 nently dyeing sails, either with the aid of an alkali or by means of an 

 oil mordant, is really an effective means of shielding the canvas from 

 the mildew fungus; and it would be of interest to determine whether 

 the altered and oxidized oil that constitutes the mordant in Turkey-red 

 dyeing might not of itself help to preserve sails, even if no tanning or 

 other coloring substance were combined with it. This last question 

 could perhaps be answered at once, even now, by persons who have had 

 experience with the use of Turkey -red cloths in damp situations. It is 

 not unfair to suppose that the oil mordant might be useful of itself, since 

 it M'ould probably tend to keep the sails drier than they would be in its 

 absence ; and in this way it might be obnoxious to the fungi, which need 

 moisture in order that they may thrive. So too with cordage; it might 

 be questioned whether ropes made from hemp that has been impreg- 

 nated with the oil mordant (and tannin), instead of with tar, would not 

 be specially serviceable in some cases. 



Note. — Since the foregoing article was written, several friends have 

 described to me a method of coloring sails, practised in the vicinity of 

 Venice, which differs essentially, both as to motive and procedure, from 

 the processes of tanning and tarring above described. It appears that, 

 far from dyeing or tanning their canvas, the fishermen at Chioggia 

 merely mix earthy pigments, such as burnt sienna and yellow ochre, 



' E. Duclaux, "Ferments et Maladies," Paris, 1882, pp. 43, 45, 50. 



