Halle, 28th. Nov. 1859.2
My dear Friend,
I have many things to report to you to day. First of all I must with much grief mention the decease of my dear father3. I already wrote to you4 of his grave illness in last winter. Though several attacks of the sickness had gone over, his health came no more back to its usual state. Sleep had left him entirely and so his forces became weaker and weaker. It was a great joy for him as well as for me that it was possible to him in summer to come over to Halle5 and see my little Johannes6. He lived in Wittekind7, a little bathing–place in our neighbourhood8. First the change of air and the joy seemed to have a good influence and he felt his state of health much better than in Berlin. But the excessive heat of last summer and new attacks of the ill (it was an organic defect in the heart) made it worse again, the [forces] were more and more consumed and so he died in my arms the 4th of August. You know how intimately our lives were connected with each other: I have lost the most conscientious father and the most faithful friend. I had communicated to you this wistful news earlier, had I not been afraid that a letter would not meet you at home, as you certainly have been abroad9.
After this sorrowful time I spent some weeks in Thüringen10, especially in [Liebza],11 where I had spent already my vacation time last summer. By chance I met both times two sisters from Warrschau12, one a widow Mrs. [Fliegner] with two children13, the other Miss Winter14. The frequent commerce and the various opportunities which the little bathing place offered to make a nearer acquaintance have made this meeting a more intimate one. I saw the ladies once more at Jena,15 where Mrs. [Fliegner] is living now, then I met Miss Winter at Dresden (where she has relations, among other: the well known Schnorr of Carolsfeld, actual Director of the Dresden Gallery of pictures).16 There, on the returnal to Warsaw she became my bride. I hope from her conscientious character not only to get a faithful wife for myself but also a true mother for my dear child17—both of which I had possessed in so high a degree in my Elizabeth,18 who will never be forgotten in my memory.
It was a peculiar misfortune that even this happy event was followed by a new affliction. I received in Dresden at the same time the news of the death of my aunt,19 the same, who after the early decease of my amiable mother20 had taken her place in the full sense of the word for my sister and me, so that I considered her always as my second mother and bore to her the full veneration and love of a son.
You see, my dear friend, that in the last time Heaven has sent me much grief and that He begins to send me new joy!
Referring to my scientific occupation I send to you several papers: one on the influence of different media in [lenses] another on the Interference of Heat. You may imagine that I lay a certain weight on this discovery, as I best know the extreme difficulties which occur in proving experimentally the Cold not in the usual sense as a want but as a [real] fact of Heat itself. Finding the cold bands which separate the warm ones in the diffracted heat, and showing their existence with a sureness, which makes it possible to observe them even for the most unexercised one, I have believed to fill up an essential void in the Doctrine of Radiant Heat.—I have proved by the thermo–multiplier the existence of the Interference of Heat in all possible principles of producing them: difference of ways; difference of substances; different reflexions; different velocity of rays. So I have repeated in the Chapter of Radial Heat21 all experiments of Thomas Young with Light.22
Reading the Paper, you will find another fact, as a secondary observation: the two groups of rays which Heat offers after the reflexion from Crystals etc. I hope you will to a certain degree be satisfied by the mode of experiments. The Interference–Colours (qualitative differences) of Heat have also been shown by the inquiry. I take the liberty to send several copies of the papers for you, Prof. Faraday and our common friend Hirst, whose address is unknown to me.
I add a paper for the London Royal Society23 as a peculiar mark (sign) of my high esteem for this, one of the first Academies in Europe. I have joined some other papers which are of a peculiar interest.
You receive:
1) 6 cards for you, Dr Hirst, Prof. Frankland,24
2) for you:
a) Memoir on the Interference of Heat,25
b) “ “ Optical Experiments26
} quite new
c) “ “ Diffraction and double Refraction of Heat27
d) “ “ Influence of Electricity on Crystals28
} not yet in your possession
e) a copy of my water rays29.
} new
3) No a and b for Dr Hirst
4) “ “ “ “ “ Prof. Faraday (with my respectful compliments)
5) for the Royal Society
a) Memoir on the Interference of Heat30 referring to:
b) “ “ on the Diffraction of Heat.31
c) Memoir on the influence of Metals on Radiant Heat,32 referring to:
d) De calore radiante disquisitions33 etc.
e) Two Papers on the influence of Crystals on Rad. Heat. Pleochroismus.34
f) On the Influence of Electricity on Crystals35
g) The Physical Qualities on Woods.36
—
A great part of my Experiments of last Summer is not yet published.
My best thanks for your very interesting memoirs on Glaciers.37
Good bye my dear friend! My Johannes sends his kindest remembrances to you, as his father’s friend.
Do not forget us!
Yours | most affectionately | Herm. Knoblauch
I am sure you will be kind enough to present my Memoirs to the Royal Society in one of the Sections with my fullest respects, and add some words about the contents.38 My best thanks for this favour before! | H. K.
I have the honour to add in the name of the naturforschende Gesellschaft von Halle39 a diploma,40 which creates you a member of this respectable society, which in the course of its existence since almost a hundred years contains the most eminent and celebrated names among their members.
Wishing to make Prof. Faraday also a fellow of it, I heard that he were so already since a longer time.
Receive this little mark of my high esteem for your scientific labours at the same time as an homage of the unaltered friendship in which I remain
Ever yours | most faithfully | Herm. Knoblauch. | Halle, | 7. December | 1859.
RI MS JT/1/K/22
RI MS JT/1/TYP/7/2502–5
Knoblauch: See letter 1605, n. 15.
Tyndall recorded a brief summary of the content of this letter in his journal for Thursday 15 December 1859, ”Knoblauch’s father is dead—He is also verlobt. I was glad to hear it, for his life in Halle seemed a lonely one.” (Journal, RI MS JT/2/13c/1167). Knoblauch’s father had been ill for a longer period, see also letter 1605.
my dear father: the politician and entrepreneur Carl Friedrich Wilhelm Knoblauch (1793–1859).
I already wrote to you: letter missing.
Halle: city in Germany, home of the University of Halle.
my little Johannes: Knoblauch’s son with his late wife, Elizabeth (see n. 17), Johannes Knoblauch (1855–1915).
Wittekind: not identified.
in our neighbourhood: Knoblauch worked at the University of Halle from 1853 onwards.
as you certainly have been abroad: Tyndall travelled through the French Alps during August 1859. See letters 1634, 1635, and 1643.
Thüringen: a region in central Germany.
[Liebza]: not identified.
Warrschau: Warsaw, capital of Poland.
widow Mrs. [Fliegner] with two children: not identified.
Miss Winter: not identified, presumed to be Knoblauch’s second wife.
Jena: city in Germany, home of the University of Jenna. It is unclear if Knoblauch was undertaking research while in Jenna.
Schnorr of Carolsfeld, actual Director of the Dresden Gallery of pictures: refers to Julius Schnorr von Carolsfeld (1794–1872).
my dear child: see n. 6.
Elizabeth: Knoblauch’s late wife, Elizabeth (1827–55).
my Aunt: not identified.
the early decease of my amiable mother: Knoblauch’s mother Emilie Henriette died very young, in 1821.
Chapter of Radial Heat: It is uncertain which of Knoblauch’s articles on radiant heat is referred to; it is possibly H. Knoblauch, ‘Über die Polarisation der strahlenden Wärme durch einfache Brechung’, Poggend. Annal., 161:2 (1852) pp. 169–88.
all experiments of Thomas Young with Light: The physician Thomas Young (1773–1829) carried out research on light, including the famous double–slit experiment which showed that light behaved as a wave.
I add a paper for the London Royal Society: Knoblauch outlined several gifts to the Royal Society, see n. 31–37.
6 cards for you, Dr Hirst, Prof. Frankland: cards missing.
Memoir on the Interference of Heat: it is uncertain which of Knoblauch’s articles on Heat is referred to. Given the timing of this letter, it may refer to Knoblauch’s article ‘Ueber die Interferenz der Wärmestrahlen’, Poggend. Annal., 184:12 (1859), pp. 610–15.
Optical Experiments: may refer to Knoblauch’s article ‘Ein Paar optischer Vorlesungs–Versuche’, Poggend. Annal., 183:6 (1859), pp. 323–6.
Diffraction and double Refraction of Heat: likely refers to Knoblauch’s article ‘Über die Doppelbrechung der strahlenden Wärme', Poggend. Annal., 150:5 (1848), pp. 1–9.
Influence of Electricity on Crystals: H. Knoblauch, ‘Über das Verhalten krystallisirter Körper zwischen elektrischen Polen’, Poggend. Annal., 159:6 (1851), pp. 289–99.
my water rays: not identified.
Memoir on the Interference of Heat: see n. 26
on the Diffraction of Heat: See n. 27.
the influence of Metals on Radiant Heat: H. Knoblauch, ‘Über den Einfluss welchen Metalle auf die strahlende Wärme ausüben’, Poggend. Annal., 177:6 (1857), pp. 161–213.
De calore radiante disquisitions: H. Knoblauch, De Calore Radiante: Disquisitiones Experimentis Quibusdam Novis Illustratae, (Berolini, 1846).
Two Papers on the influence of Crystals on Rad. Heat. Pleochroismus: H. Knoblauch, ‘Über die Abhängigkeit des Durchgangs der strahlenden Wärme durch Krystalle von ihrer Richtung in denselben’, Poggend. Annal., 161:2 (1852), pp. 169–88, and likely refers to H. Knoblauch, ‘1. Gangunterschied durch ungleiche Wegeslängen in einem und demselben Medium’, Monatsberichte der Königlichen Preuss. Akademie der Wissenschaften zu Berlin, (1859) pp. 565–66.
Influence of Electricity on Crystals: see n. 28.
The Physical Qualities on Woods: H. Knoblauch, Ob bei verschiedenen Holzarten ein gewisser Zusammenhang zwischen den un ihnen beobachteten Eigenschaften (Halle: 1858).
memoirs on Glaciers: Refers to Tyndall’s book The Glaciers of the Alps, which was published in 1860.
I am sure you will be kind enough to present my Memoirs to the Royal Society in one of the Sections with my fullest respects, and add some words about the contents: It is uncertain if and when Tyndall did this, and it does not appear that Knoblauch’s papers were published in the Proc. Roy. Inst. Several of his articles did appear in the Phil. Mag., including: H. Knoblauch, ‘LVI. On the Connexion between the Structure and the Physical Properties of Wood’, Phil. Mag., 115:17 (1859), pp. 348–52.;
H. Knoblauch, ‘XVI. On the Interference of Heat’, Phil. Mag., 125:19 (1860), pp. 126–8; and H. Knoblauch, ‘XXI. Intelligence and Miscellaneous Articles. Optical Lecture-Experiments’, Phil. Mag., 125:19 (1860), 162–4. Tyndall frequently reference Knoblauch, for example in his Friday evening lecture at the RI ‘On the Action of Gases and Vapours on Radiant Heat’ (January 18, 1861).
naturforschende Gesellschaft von Halle: scientific society founded in 1779.
a diploma: Tyndall recorded receipt of this diploma in his journal for Thursday 15 December 1859, “He sent me a diploma from Halle. His letter is full of warm friendship.” (Journal, RI MS JT/2/13c/1167).
Please cite as “Tyndall1662,” in Ɛpsilon: The John Tyndall Collection accessed on