Ferdinand von Mueller

Friday

1

The contents make it clear that this letter is closely linked to M to W. Woolls, 15 December 1876, to which it is attached in the Mitchell Library's bound volume of Woolls's correspondence, and M to W. B. Clarke, 25 December 1876. This suggests that it was probably written either as a second letter to Woolls on Friday 15 December 1876, or on the following Friday, 22 December 1876.

Hot days like these here now, dear Dr Woolls, ought to lead the destructors of trees to reflection.

2

A lecture by W. B. Clarke in which he advocated better conservation of forests, published in the Sydney morning herald on 4 November 1876, attracted fierce criticism from L. Fane de Salis, MLC, and a controversy in the pages of the newspaper ensued.

Every tree is a factor (however individually insignificant in the total sum) in the calculation of temperature. The formula is a very simple one: vapor is water plus heat. Water is vapor minus heat. To retain water or condense vapors by trees is reducing heat, and this effect we cannot extend too much in a country like Australia with its hot dry summer winds. Let pastoral animals enjoy as much shade as they can get, and cool with foliage as much area as you can in our country, though the superabundance of overwet jungleforests of tropical forests in fern regions must be reduced and opened up for aeration and evaporation. We need not fall from one extreme to the other. Were I to advocate extreme measures, then the word "pedant" hurled at me undeservedly

3

See M to W. B. Clarke, 25 December 1876, and the notes thereto, where the dispute is summarized and relevant passages quoted including several critical of M.

might be deserved.

Remember also the chemical ancient adage: "corpora non agunt nisi fluida"

4

Bodies do not act unless fluid.

Trees cannot decompose and bring to the surface the mineral nourishment of plants, if the strata below are not rendered to some extent moist, so that the absorbing process of the root spongioles can actively proceed. In my new edition of the "industrial plants"

5

B76.12.04.

I have alluded to many grasses, which grow in the shade of trees; let such be copiously introduced to improve woody pastures.

In the journal of applied science is just alluded to the use of oil to calm the waves in sea disasters.

6

The original article has not been found, but it was reprinted in newspapers; see, for example, 'Oiling the sea', Leader (Melbourne), 27 January 1877, p. 5.

I was well aware of this, as the fishermen on the scandinavian coast avail themselves of "Thran"

7

fish oil. Information presumably acquired by M in Schleswig-Holstein in his youth.

in emergencies, when wrecks occur. Indeed my friend Mr Simmonds

8

Not positively identified.

might have quoted the well known proverb: "to put oil on the troubled waters". It seems however not known how very small quantity of any oily fluid suffices to prevent the air of a furious gale to penetrate the water for wide distances. You might send on this hurried note to our reverend friend Clarke.

Mr Russell

9

H. C. Russell, Government Astronomer of NSW, who was also in charge of the colony's meteorological service?

will find some of the causes explained in my forest-lecture in regard to trees dying over wide distances apparently spontaneously. The causes are however manyfold: exempli gratia: trampling into hard masses the soil around trees cutting away the sheltering & moistening & cooling underwood. Destruction of foliage by insects: ultimate effect of bush fires. Seasons of unusually severe frosts. Even superabundance of opossums occasionally changes in the features of a country by diminution of timber or by traffic, sending a superabundance of stagnant water to localities formerly moderately moist only &c &c