Going Dutch_ How England Plundered Holland's Glory - Lisa Jardine [89]
I could not forbeare to shew your Grace by these lines how verily mindfull I am of the many favours she hath been pleased to bestow upon me in former times, especially of those favours [in your laboratory], Madam, which I remember did cost you many a white petticoat a week.42
In the spring of 1657, following a visit to the Rubens House and an enjoyable session together discussing natural philosophy, Huygens sent Margaret some specimens of ‘Prince Rupert’s drops’ – small teardrop- shaped glass vessels, with extraordinary physical properties. The drops could withstand the pressure of considerable weights placed on them, and were unbreakable even when struck squarely with a hammer. Yet if even the smallest tip of their tails was snapped off with a finger, the whole thing exploded into powder with a loud report. Huygens requested Margaret to study the properties of these curious glass baubles and to offer him a scientific explanation:
I had the honour to heare so good solutions given by your Excellencie upon divers questions moved in a whole afternoone, she was pleased to bestowe upon my unworthie conversation, that I am turning to schoole with all speede, humbly beseeching your Exellencie may be so bountifull towards my ignorance, as to instruct me about the natural reason of these wonderfull glasses, which, as I told you, Madam, will fly into powder, if one breakes but the least top of their tailes, whereas without that way they are hardly to be broken by any waight or strength. The King of France is as yet unresolved in the question, notwithstanding he hath been curious to move it to an assembly of the best philosophers of Paris, the microcosme of his kingdome.
With his customary exquisite decorum, Huygens explained in his letter how Margaret should handle the drops if her feminine sensibility made her nervous of the explosions caused when their tails were snapped off:
Your Exellencie hath no cause to apprehend the cracking blow of these innoxious gunnes. If you did, Madam, a servant may hold them close in his fists, and yourselfe can break the little end of their taile without the least danger. But, as I was bold to tell your Exellencie, I should bee loth to beleeve, any female feare should reigne amongst so much over- masculine wisdom as the world doth admire in her. I pray God to blesse your Exellencie with a dayly increase of it, and your worthie selfe to graunt that amongst those admirers I may strive to deserve by way of my humble service the honour to be accounted.43
Margaret replied a week later. She thanked Huygens for his letter and accompanying poems in Dutch, and gave at length her views on the causes of the violent reactions when the drops were broken. In her view there was a tiny quantity of volatile material trapped inside each drop, which exploded on contact with the air:
To myne outward sense these glasses doe appeare to have on the head, body or belly a liquid and oyly substance, which may be the oyly spirrits or essences of sulpher; alsoe the glasses doe appeare to my senses like the nature or arte of gunns and the spirrit of sulpher as the powder; where although they are charged, yet untill they bee discharged, give no report or sound; the discharging of these glasses is by the breakeinge of a piece or part or end of the tailes, where the discharging of guns are by much [match?] firelockes, scrues or the like, which setts fire or gives vent to the powder, but these sulpherousse spirrits, having as it seemes a more force- able nature, it doth viollently thrust itselfe out, where itt findes vent, like as wind, but rather like fire, being of a firy nature, and may have the effects of bright shining fire, which, when it has noe vent, lyes as dead, but as soone as it can ease out a passage, or findes a vent, it breakes forth in a violent crack or thundering noisse.