Evaluating the Evidence 16.2: “An Account of a Particular Species of Cocoon”

“An Account of a Particular Species of Cocoon”

To disseminate its members’ work, the Royal Society of England published the results of its meetings in the Philosophical Transactions of the Royal Society. The passage below is excerpted from a presentation made to the society in the mid-eighteenth century by the Reverend Samuel Pullein, a graduate of Trinity College in Dublin. A relative of the governor of Jamaica, Pullein became fascinated by the idea of introducing silkworm cultivation to the American colonies. His presentation exemplifies the contribution of many minor enthusiasts to the progress of science in this period and the importance of colonialism to the new knowledge.

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Having lately seen the aurelia of a particular species of caterpillar, I judged, from its texture and consistence, that there might be procured from it a silk not inferior to that of the common silk-worm in its quality, and in its quantity much superior. I have made some experiments on this new species of silk-pod, which strengthen this opinion.

This pod is about three inches and a quarter in length, and above one inch in diameter; its outward form not so regular an oval as that of the common silk-worm; its consistence somewhat like that of a dried bladder, when not fully blown; its colour of a reddish brown; its whole weight 21 grains.

Upon cutting open this outer integument, there appeared in the inside a pod completely oval, as that of the silk-worm. It was covered with some floss-silk, by which it was connected to the outer coat, being of the same colour. Its length was two inches; its diameter nearly one inch; and its weight nine grains.

The pod could not be easily unwinded, because it was perforated by the moth: but, upon putting it in hot water, I reeled off so much as sufficed to form a judgment of the strength and staple of its silk.

The single thread winded off the pod in the same manner as that of the common silk-worm; seeming in all respects as fine, and as tough. I doubled this thread so often as to contain twenty in thickness; and the compound thread was as smooth, as elastic, and as glossy, as that of the common silk-worm. I tried what weight it would bear; and it bore fifteen ounces and a half, and broke with somewhat less than sixteen, upon several trials. . . .

The caterpillar which produces this pod is a native of America. It was found in Pennsylvania: the pod was fixed to the small branch of a tree, which seemed to be either of the crab or hawthorn species. . . .

I do not conceive that it will be at all difficult to find out the caterpillar, or the tree it feeds on; or to reel such a quantity of the silk as shall, when woven into ribband, more fully demonstrate whether it be of that value which I judge it. For by comparing it with the cocoon of the wild Chinese silk-worm, from which an excellent species of silk is made, I have no doubt of its being the same species; and would be glad if, by this memorial, I could induce the people of America to make trial of it.

EVALUATE THE EVIDENCE

  1. What is Pullein’s aim in presenting his research to the Royal Society? How does he try to establish the credibility of his claims about the silkworm?
  2. In what ways does this document belong to the “Scientific Revolution” as discussed in this chapter? What does Pullein’s presentation tell us about the nature of “science” presented to the Royal Society in the mid-eighteenth century?

Source: “An Account of a Particular Species of Cocoon, or Silk-Pod, from America,” Reverend Samuel Pullein, M.A., Philosophical Transactions of the Royal Society 15 (1759): 54–57.