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Link: • Peter Collinson to Carl Linnaeus, 15 September 1763 n.s.
Dated Sepr:15:1763. Sent from London (Great Britain) to Uppsala (Sweden). Written in English.


Peter CollinsonCollinson, Peter (1694-1768).
British. Merchant and amateur naturalist
in London, corresponded with many
scientists. Correspondent of Linnaeus.
has read Linnaeus’s letter of November 23, 1762 [this letter has not come down to us], and he asks how he could doubt any longer that swallows hibernate under water. However, he again suggests that Linnaeus examines them anatomically to discover the wonderful apparatus that is necessary to make this possible. It is contrary to animals that live in the air to live under water for so many months.

If Linnaeus cannot do so himself, he will no doubt find one of his numerous pupils who could catch a number of these birds at the time when they leave and examine their anatomy.

t is really worthy of Linnaeus’s dignity to give definite proof of this issue, where the opinions of learned men differ widely.

Collinson thinks the important apparatus must be found somewhere near the heart of the bird. In addition, fishermen could be encouraged by some reward to bring to Linnaeus or his pupils any swallows that they happen to take up from the water or from under the ice. This is particularly important, since it might be that one species only hibernates in this way, while others do not.

Collinson is very eager to have this done, since he is as sure that he has seen them flying away twice in great numbers as Linnaeus is that he has seen them taken from under the water and revive.

In all the rivers of England, Wales, Scotland and Ireland, there are very many fishermen, and none of them has ever reported that swallows have been found under the water during the winter. Collinson wonders how Linnaeus could explain this or prove that swallows in Sweden are of a different kind.

Collinson returns to his experiments, but he is not happy to perform them himself, so he hopes others will take care of that. When the swallows are about to leave, they gather in large numbers in reeds and bushes, so it cannot be difficult to catch enough of them.

First, five or six swallows should be caught, tied to weights and sunk under water. If they survive for a week, they can live under water in the lakes. However, this experiment would force them to do something against their nature.

Another design, which avoids this difficulty, means filling a wide tub with sand and water to a foot from the brim. Then, a board is put on the water, some swallows are placed on the board, and the tub is covered with a net. If the swallows dive from the board and live under water, this will prove Linnaeus’s assertion.

Collinson ends with some honouring phrases, congratulating Linnaeus for his nobility and wishing him a long and healthy life.

P.S. 1. Collinson mentions that Linnaeus had promised him a copy of, Systema naturae,10th editionLinnaeus, Carl Systema
, 10th edition (Stockholm
1758-1759). Soulsby no. 58.
, five years ago but that he has not yet received it. The waiting is tedious.

P.S. 2. Collinson sends his regards to Backe [Abraham BäckBäck, Abraham (1713-1795).
Swedish. Physician, president of the
Collegium Medicum, Stockholm. Close
friend of Linnaeus. Correspondent of
] and Bierken [Pehr af BjerkénBjerkén, Pehr af
(1731-1774). Swedish. Pupil of
Linnaeus. City medical officer,
Stockholm. Correspondent of Linnaeus.

P.S. 3. When the tall Siberian larkspur has flowered, Collinson has cut it close to the ground, and then it produces new branches and flowers again. In this way, it flowers twice in a year.

P.S. 4. In England, it was very dry in the spring and summer until the middle of July, but after that, it has rained almost every day. The crops come in great plenty, but the weather is not good for the harvest.

P.S. 5. Collinson’s large magnolia has flowered finely. Collinson finds it remarkable that magnolias have a continuous flowering for two or three months.

As the last part of the letter, Daniel SolanderSolander, Daniel (1733-1782).
Swedish. Naturalist, explorer. Student
in Uppsala under Linnaeus and Johan
Gottschalk Wallerius. Went to London in
1760. Curator of natural history
collections at the British Museum.
Botanist on Cook’s first voyage
1768-1771. Joseph Bank’s librarian.
Correspondent of Linnaeus.
has written in Swedish that Collinson has submitted a treatise on the migration of swallows to the Royal Society, LondonRoyal Society, London,
British. The Royal Society was founded
in Oxford in 1645 and sanctioned as a
royal society in 1662.
[Solander refers to Collinson’s, “A letter to the honourable J. Th. Klein”Collinson, Peter “A letter to
the honourable J. Th. Klein, secretary
to the city of Dantzick, from Mr Peter
Collinson, F.R.S. concerning the
migration of swallows”, Philosophical
51 (1760), II, 459-464.
], and promised to collect further information on the matter, which makes him very anxious to get an answer from Linnaeus.


a. original holograph (LS, XVII, 75-76). [1] [2] [3]


1. A selection (1821), vol. 1, p. 59-63   p.59  p.60  p.61  p.62  p.63.
2. “Forget not Mee & My Garden ...” (2002), p. 248-250 .