-Letter of 16 May 1650 (from Leiden to Nijmegen): "Delicti hujus mei ut facilis apud te excusatio futura est, ita metuo ut pari cum successu apud d’Ewesium tentetur. Rogo igitur te ac obsecro, ut qualiscunque causae nostrae patrocinium suscipias, hominemque si quid taciturnitati nostrae succensuit, places. Id enim ut fieret, postquam ad meos reversus sum, praecipuae mihi curae fuit. Scripsi hic ad illum, ut vides, meque, quantum potui, hoc nomine purgavi. De nummis aureis nihil polliceri possum, et, ut aperte tecum agam, sera ejus vota esse existimo: addixi enim illos Serenissimae Reginae nostrae, quae, ut elegantiarum omnium, ita rei nummariae inprimis studiosa est: sed cum maximam hujus supellectilis copiam ex Italia exspectet, praeter illos, quos jam possidet ex Germania allatos, futurum fortassis est, ut meos mihi relinquat.
Scribit d’Ewesius se parare luci Theatrum nummarium, in quo nummos hactenus ineditos sit exhibiturues, cujus notae nonnullos apud me existimo, plureas apud Reginam.
(Just as it will be easy for me to make my excuses for my failure [to reply to his letter], so I am anxious for a similar outcome with D’Ewes. I therefore ask and beg you to think up any defence of my case and satisfy the man if he is angry with my silence. That this should be so, after I have come back to my affairs, is a matter of great importance to me. I wrote this to him, as you can see, and I have excused myself in this manner, as far as I am able. I can promise nothing about the gold coins, and, to be frank with you, I think his wishes have come late: for I have granted them to our Most Serene Queen, who is keen on all matters of good taste, and particularly so on coins: but, since she is expecting a very large quantity of this material from Italy, it may perhaps be that, except for those brought from Germany which she already owns, she may leave mine for me. D’Ewes writes that he is preparing a Numismatic Theatre for the light, in which he will publish hitherto unpublished coins. I think I have a few of this sort, and there are many with the Queen.) (G. C. in de Betouw (ed.), De lucernis veterum reconditis in agro Neomagensium suburbano (Nijmegen, 1783), pp. 41-43)